Best Grease for Grease Gun: Sticky, Tough & Reliable Picks

Grease that slips away under pressure or washes out in wet environments causes machines to wear out faster and fail unexpectedly. Components lose their protective film, leading to rust, friction damage, and downtime.

The best grease for grease gun must offer high adhesion, temperature resilience, corrosion protection, and compatibility with grease gun fittings to truly hold up under demanding conditions.

Many greases either lose tackiness or break down under heat and moisture, forcing repeated applications and risking mechanical failure. The following selections bring together formulations that cling, protect, and perform where it counts.

Reliable Greases for Effective Grease Gun Lubrication

Choosing the right grease impacts how well machinery performs under pressure, temperature changes, and wet environments. These options stand out for durability and staying power.

1. Lucas Oil Heavy-Duty Red N Tacky Grease 3 Ounce Tub Combo Pack for Extreme Conditions

Finding grease that won’t simply drip away under pressure or wash out in wet conditions can be a challenge. Lucas Oil answers with their specialized formula engineered to cling firmly even on the toughest surfaces. Its exceptionally sticky texture means the grease stays put, reducing the need for constant reapplication in demanding work environments.

Thick and durable, this lubricant offers reliable performance in high-load situations and protects components against corrosion. The resistance to water and breakdown at elevated temperatures extends machinery life and boosts operational efficiency. You get consistent coverage with a product designed to endure real-world wear.

Lucas Oil’s design also addresses common frustrations by minimizing messy leaks that plague typical greases in tubes. Its packaging keeps the grease intact and ready for smooth loading into grease guns, making it easier to manage on job sites or farms. Users appreciate how the texture balances ease of application with staying power.

Each 3-ounce tub delivers a measured supply of thick lubricant that targets bearings and other parts needing robust defense from environmental stress. The combination of heavy-duty adhesion and corrosion prevention makes it a standout choice within Lucas Oil’s lineup.

Best for: Professionals and enthusiasts managing equipment exposed to wet and heavy-load conditions who require a dependable grease to hold firm and protect critical components.

Pros:

• Highly adhesive formula that resists displacement
• Strong protection against corrosion in wet environments
• Maintains integrity under high pressure and heat
• Packaging designed to reduce leaks and waste
• Compatible with most grease guns for easy application

Cons:

• Smaller 3-ounce size may require multiple tubs for extensive use

2. Valvoline Multi-Vehicle Heavy-Duty Red Grease Cartridge – High Temp, Water Resistant, 14.1 OZ

Handling demanding lubrication tasks often means trusting materials that hold up under pressure and heat. Valvoline’s multi-vehicle red grease offers extreme-pressure protection and performs reliably across a wide temperature range from -5°F to 250°F. Its excellent water resistance makes it stand out for applications exposed to moisture or harsh conditions.

Engineered specifically for components like disc brake wheel bearings, suspension parts, and steering linkages, this lithium-based formula adheres firmly to metal surfaces while reducing wear. The cartridge format simplifies loading into grease guns and keeps the product manageable during maintenance routines.

High-temperature environments challenge many greases, but Valvoline’s formulation maintains its integrity without breaking down, providing consistent lubrication even in intense heat. The red hue isn’t just for show—it signals a robust composition designed to stay put and keep moving parts running smoothly.

Use this grease to tackle chassis components and universal joints where reliability and lasting lubrication can prevent costly repairs. Valvoline’s reputation for quality blends well with the functional design to offer a dependable solution for different vehicles.

Best for: Mechanics and technicians servicing various automotive parts needing heat-resistant and water-repellent lubrication.

Pros:

• Wide temperature tolerance from -5°F to 250°F
• Strong water resistance prevents washout
• Extreme-pressure formula protects critical moving parts
• Lithium-based grease offers stable consistency
• Convenient 14.1-ounce cartridge for easy use with grease guns

Cons:

• Cartridges may be susceptible to leakage if not stored properly

3. AtomLube Ultra Heavy Duty Red Grease 2-Pack – Waterproof, High-Temperature Lubricant for Heavy Equipment

Applying a lubricant that withstands intense pressure and temperature variations without slipping off can change how machines perform. AtomLube’s Ultra Heavy Duty Red Grease offers exceptional adhesion to metal surfaces, minimizing wear and corrosion under tough conditions. Its heavy-duty formulation provides a durable shield against friction for semi-truck accessories and industrial components.

Designed as a multi-purpose lubricant, it excels with an NLGI #2 certified consistency that balances thickness and pumpability, avoiding issues like clogs or mess during application. Its waterproof nature keeps lubricated parts safe from moisture washout, prolonging lubrication intervals and reducing maintenance frequency.

The grease penetrates complex machinery surfaces by leveraging nano-engineering technology, resulting in extended service life and improved equipment reliability. The bright red tint serves a practical function by highlighting applied areas for quick inspection, especially useful in professional settings.

Each 14-ounce tube fits standard grease guns and delivers smoother application. The pack of two tubes ensures you have enough for ongoing upkeep, helping prevent downtime due to bearing or chassis failure. AtomLube commits solid performance with this lubricant designed for extreme pressure scenarios and lasting protection.

Best for: Heavy machinery operators needing a robust grease that stays put during high-temperature and high-pressure conditions.

Pros:

• Strong resistance to washout and oxidation
• Effective in both wheel bearings and chassis lubrication
• Thick yet pumpable consistency compatible with grease guns
• High temperature tolerance up to 257°F
• Dual-pack offers good supply for ongoing maintenance

Cons:

• Might be too heavy-duty for light or delicate machinery parts

4. Birchwood Casey Long-Lasting Gun Grease for Superior Rust Protection & Maintenance

Applying a durable, protective layer on metal surfaces preserves their function and longevity far beyond occasional cleaning. Birchwood Casey offers a grease that acts as a thin yet resilient film, guarding your firearm’s components from the slow creep of rust and corrosion. Its paste form spreads evenly to coat every nook and cranny, creating long-lasting rust resistance that outperforms many conventional lubricants.

Formulated specifically for guns, this lubricant sets itself apart with a balanced thickness that provides a protective barrier without becoming excessively greasy. While its primary role is preservation, it also helps maintain metal surfaces’ smooth feel and shine after application, contributing to reliable operation over time. The compact 3-ounce jar is convenient for quick touch-ups at the range or after field use, making it handy in various scenarios.

The brand’s reputation for quality in shooting accessories is evident in the grease’s performance consistency. Frequent users praise how a small amount goes a long way, making the product efficient without compromising on protection. Its universal compatibility means it fits a wide range of firearm types and finishes, from blued steel to stainless.

Birchwood Casey’s grease is more than a lubricant — it serves as a protective shield that keeps your investment performing and looking cared-for after every use or storage period.

Best for: Shooters and hunters needing robust, lasting preservation of firearm metal surfaces against rust and wear.

Pros:

• Creates a thin protective film that resists rust and corrosion
• Long-lasting effect, reducing frequent reapplications
• Compact jar ideal for field or range use
• Effective on multiple metal finishes including blued and stainless steel
• Trusted brand with decades of experience in gun maintenance

Cons:

• May be thicker than some prefer for internal action lubrication

5. AtomLube All Purpose Grease 2-Pack, Heavy-Duty Multi Function Lubricant Tubes

Handling tasks that involve machinery in harsh conditions demands a lubricant that doesn’t quit. AtomLube’s all purpose grease delivers long-lasting lubrication with enhanced resistance to oxidation and washout. This quality lets you extend maintenance intervals without sacrificing equipment protection.

Engineered with a combination of heavy-duty, multi-purpose, and marine grease qualities, it adheres firmly to metal surfaces. This strong adhesion minimizes friction and corrosion, even when exposed to severe environments and extreme pressures. The grease’s waterproof nature adds a layer of reliability where moisture threatens performance.

Manufactured in the USA, this product meets the GC-LB performance classification, supporting wheel bearing and chassis lubrication needs for advanced automotive care. The convenient two 14-ounce tubes are designed to fit grease guns smoothly, allowing precise application where you need it most.

With AtomLube, you’re choosing a formula that withstands high temperatures and demanding conditions while reducing downtime through its durable protective film. Strong stay-in-place power ensures that lubrication remains effective past initial application.

Best for: Operators managing automotive, marine, and truck equipment requiring dependable, multi-functional lubrication.

Pros:

• Combines heavy-duty, multi-purpose, and marine grease benefits
• High resistance to oxidation and washout increases lifespan
• Waterproof and corrosion-fighting properties
• Certified to NLGI GC-LB standard for automotive use
• Convenient tube packaging fits most grease guns

Cons:

• Tube format may be less suited for very large scale industrial applications
• May require frequent reapplication under extremely heavy load conditions

6. Wolf’s Head Premium Tacky Red Lithium Complex Grease for Heavy-Duty Wheel Bearings & Chassis Protection, 14 oz Tube, Pack of 10

Keeping wheel bearings and chassis components reliably lubricated under tough conditions demands more than just any grease. Wolf’s Head delivers a tacky formula that clings tightly to surfaces, preventing premature loss and ensuring continuous protection where it’s needed most.

Built to withstand extremes, this lithium complex grease handles temperatures from -10°F up to 375°F, maintaining its consistency and effectiveness even under heavy loads. It offers a high dropping point above 500°F, making it suitable for applications exposed to severe heat.

Formulated to reduce friction and resist shock loads, it extends the life of critical machinery parts by forming a strong, durable film. Whether on wheel bearings, U-joints, or 5th wheels, it safeguards against wear and tear during demanding use.

Water resistance and corrosion protection add layers of defense in damp or dirty environments, keeping components running smoothly without frequent reapplication. Over 140 years of American manufacturing craftsmanship by Wolf’s Head underscore its trusted reputation in automotive and heavy equipment maintenance.

Best for: Professionals needing long-lasting lubrication for automotive wheel bearings, agricultural machinery, and industrial chassis components operating under tough conditions.

Pros:

• Strong adherence with tacky, stay-in-place formula
• Wide operating temperature range and high heat resistance
• Excellent extreme pressure and wear protection
• Resists water washout and corrosion in harsh environments
• Trusted, American-made brand with longevity

Cons:

• Tube packaging may require compatible grease guns for ease of use
• Highly specialized grease might be more than needed for light-duty applications

7. Slip2000 Extreme Weapons Grease Syringe – Synthetic High-Performance Lubricant, 1 oz

Precision lubrication demands a formula that can withstand extreme conditions without breaking down or slipping away. Slip2000’s synthetic grease syringe delivers long-lasting protection by forming a durable barrier against friction and corrosion on metal surfaces.

Designed with high-pressure applications in mind, it handles intense mechanical stress while maintaining smooth operation on locking lugs, bolts, and slides. Its balanced viscosity applies smoothly yet clings firmly, avoiding the messiness of thinner oils or the heaviness of conventional greases.

The formula resists heat up to 750°F, making it reliable through rapid firing or prolonged use where temperature spikes tend to degrade lesser lubricants. Slip2000’s non-toxic composition prioritizes safety without sacrificing performance, suitable for firearm maintenance and other precision equipment.

Application is precise thanks to the convenient syringe packaging, allowing controlled dispensing exactly where the lubricant is needed. Its unique synthetic blend also facilitates simple cleanup, with residues that don’t attract grime or cause buildup.

Durability against wear and corrosion assures better longevity for mechanical components, enhancing reliability and quiet function.

Best for: Enthusiasts and professionals requiring dependable, clean lubrication under high stress and heat conditions.

Pros:

• Resists heat up to 750 degrees Fahrenheit
• Maintains lubrication under intense pressure
• Non-toxic and safe for users
• Easy precision application with syringe design
• Long-lasting anti-corrosion protection

Cons:

• May require extra effort to clean off after extended use
• Small quantity might necessitate multiple units for heavy users

8. LubriMatic Multi-Purpose Lithium Grease 3 oz. Cartridges Pack for Mini Guns

Handling frequent maintenance requires a grease that matches the task without extra mess or fuss. LubriMatic’s lithium-based formula offers reliable lubrication performance across automotive, agricultural, and industrial equipment. Packaged in convenient 3 oz. cartridges, it fits mini grease guns perfectly for controlled application.

Strong enough to maintain critical points yet designed for ease of use, this grease resists washing off under high stress and elevated temperatures up to 350°F. The NLGI #2 viscosity strikes a balance, providing easy pumping while still staying put where applied.

With a smooth consistency, it reduces dispensing effort and is less likely to clog or drip during use. The compact cartridges also minimize mess compared to bulk containers, saving time on cleanup. LubriMatic’s long-lasting blend keeps parts moving and protects against wear in demanding environments.

Suitable for homeowners and professionals alike, these cartridges are tailored for mini grease guns, making refills straightforward and neat. The brand’s product holds a solid reputation for sustained high performance in varied lubrication needs.

Best for: Those requiring efficient, easy-to-apply lubrication across small to medium machinery maintenance tasks.

Pros:

• Durable formula rated to 350°F for heavy-duty applications
• 3 oz. cartridges fit standard mini grease guns for neat dispensing
• Lithium base offers balanced consistency and sticking power
• Multipurpose use on automotive, agricultural, and industrial equipment
• Reduces mess compared to bulk grease loading

Cons:

• Smaller cartridge size may require frequent replacement for very large equipment

9. STAR BRITE Heavy-Duty White Lithium Grease – Durable Lubricant Cartridge for Marine and Industrial Use

Reducing wear on equipment through robust lubrication can be a challenging task when facing fluctuating weather and tough working environments. STAR BRITE’s formula enhances machinery performance by cutting friction and slowing wear, proving resilient where many greases fail.

Designed to resist temperatures soaring up to 350°F, it keeps gears, cables, chains, and joints operating smoothly even under intense heat. Its water-resistant nature protects moving parts from moisture-related damage, making it suitable for harsh outdoor and marine settings.

The grease features a white tint that offers an immediate visual check, so you know which surfaces have been treated without guesswork. Furthermore, it creates a reliable barrier against rust and corrosion, guarding valuable machinery components over time.

Compatible with most standard grease guns, including STAR BRITE’s own pistol grease gun model, this high-viscosity lubricant simplifies application while fitting conveniently in a 14-ounce cartridge. Manufactured in the USA, it reflects a legacy of quality in maintaining automotive, industrial, and marine equipment.

These qualities combine to energize equipment uptime and reduce maintenance interruptions.

Best for: Operators needing a grease that withstands extreme conditions across marine, automotive, and industrial maintenance tasks.

Pros:

• Exceptional high-temperature tolerance up to 350°F
• Water-resistant formula ideal for wet environments
• Strong corrosion and rust protection for longer equipment life
• White color for easy application verification
• Fits standard grease guns, enhancing ease of use

Cons:

• May be messier in application for some users compared to other grease types
• Thickness could require extra effort with lower-powered grease guns

10. GREASECO Multi-Purpose Lithium Grease Tube for Machinery and Equipment Lubrication

GreaseCo’s amber lithium grease tube offers durable lubrication that adapts to various everyday applications. Its versatility stands out for machines ranging from trailers to lawn equipment, improving component function across wheel bearings, chains, and small motors.

Designed with an ISO 160 base oil viscosity, the grease balances fluidity and protection under moderate loads and temperatures. It includes an additive package rich in anti-wear and oxidation inhibitors to prolong equipment life while combating corrosion and degradation, even in challenging environments.

Water resistance plays a role here, preventing washout and safeguarding metal surfaces exposed to moisture. Whether you’re dealing with garage doors or agricultural pivots, this grease keeps mechanism movements smooth and reduces downtime.

The convenient 14-ounce tube is easy to load in grease guns, making maintenance quicker, cleaner, and more efficient. GREASECO’s general-purpose formula ensures reliable performance in industrial, automotive, and home workshop contexts where diverse working parts demand steady care.

Best for: Those maintaining light to moderate machinery in agriculture, automotive, home, and industrial workshop settings looking for effective, versatile lubrication.

Pros:

• Broad spectrum of applications for multiple equipment types
• Effective water resistance to protect against corrosion
• Long-lasting, anti-wear protection with oxidation inhibitors
• ISO 160 base oil ensuring balanced viscosity
• Simple cartridge design suited for grease guns

Cons:

• Performance may be limited for extremely high-temperature or heavy-load industrial use
• Single tube size might not suit all volume needs

Quick Guide: Best Grease for Grease Gun Feature Analysis

Product Name	Base Thickener / Material	Temperature Range	Container Type & Size
Lucas Oil Red N Tacky	Grease, Oil Blend Tacky Formula	Not Specified High-adhesion in wet conditions	Tub, Multiple sizes 3 oz tube combo pack
Valvoline Multi-Vehicle Red	Lithium Thickened High-temp formula	-5°F to 250°F	Cartridge 14.1 oz cartridge, case of 10
AtomLube Ultra Heavy Duty Red	Metal based NLGI Grade #2	Up to 257°F	Tube 14 oz tubes, 2-pack
Birchwood Casey Rig Gun Grease	Paste form Plastic Container	Not Specified Long-lasting anti-rust	Jar 3 oz jar
AtomLube All Purpose Grease	Metal based NLGI Grade #2	Not Specified Waterproof & multi-use	Tube 14 oz tubes, 2-pack
Wolf’s Head Red Grease NLGI #2	Lithium Complex Heavy-duty formula	-10°F to 375°F Dropping point > 500°F	Tube 14 oz tubes, pack of 10
Slip2000 Extreme Weapons Grease	Synthetic Light grease in syringe	Up to 750°F	Syringe 1 oz syringe
LubriMatic Multi-Purpose	Lithium thickener NLGI #2	Up to 350°F	Cartridge 3 oz cartridges, pack of 3

How to Choose Grease That Actually Works For Your Grease Gun?

Picking the right grease isn’t just about brand or color. It’s about performance features tailored to your equipment’s demands. Below are key factors to verify before committing.

Thickener Type and Consistency

The thickener gives grease its structure and helps it stick to metal surfaces. Common types include lithium complex, polyurea, calcium sulfonate, and synthetic blends. The grease’s consistency is linked to the NLGI grade, with #2 being the standard for most grease guns.

For instance, Wolf’s Head uses lithium complex thickeners to offer durability and water resistance. On the other hand, synthetic thickeners like those in Slip2000 excel at handling high temperatures. The grease’s consistency directly impacts how easily it can be pumped and how long it stays put.

Choosing the wrong thickener can lead to grease that either leaks out too fast or is too stiff to apply smoothly. This causes poor lubrication or messy maintenance, so picking the right type is key for effective performance.

Temperature Range and Stability

Temperature range defines where grease performs well without melting, hardening, or separating. Having a grease with a broad, stable temperature range is key for engines, heavy gear, or firearms facing hot bursts or cold starts.

Slip2000 handles heat up to 750°F, fitting for harsh conditions. Valvoline works between -5°F and 250°F, making it a solid choice for cars and mixed-use vehicles. Stability means the grease stays intact and sticks well even when things heat up during use.

Grease used beyond its set temperature range breaks down fast, loses its protective layer, and speeds up wear. This undermines the whole point of applying grease in the first place.

Water Resistance and Adhesion

Water resistance means a grease can hold up against moisture without washing away. Adhesion is about how well it sticks to metal surfaces, even under pressure. These qualities matter a lot when gear faces wet or outdoor conditions.

Greases with tacky formulas, like Lucas Oil’s Red N Tacky, provide a strong grip that keeps lubrication in place. Brands such as Valvoline and AtomLube focus on waterproofing, helping protect wheel bearings and chassis parts from rust and damage caused by water and mud.

Choosing a grease that lacks these features risks it being washed out during use. This leaves metal exposed to corrosion and wear, which can cause equipment failures, longer downtime, and higher maintenance expenses.

Compatibility with Grease Guns and Application Method

Choosing grease that works well with your grease gun helps avoid clogs and pressure issues. Some greases come in cartridges, like Valvoline and LubriMatic, which fit mini or standard guns easily. Others, like tubs or syringes, need manual loading or special gun types for application.

The grease’s consistency and packaging affect how smoothly you can apply it. Thick pastes such as Birchwood Casey’s require scooping, which takes more time but offers excellent rust protection, especially for firearms.

Picking the wrong grease packaging or consistency can lead to wasted product, difficulty applying grease, or uneven lubrication. Matching grease type to your application method keeps maintenance efficient and effective.

Additive Packages and Corrosion Protection

Greases come with additives such as anti-wear agents, rust inhibitors, and extreme pressure (EP) compounds that help protect parts from damage. These additives play a big role in extending the life of machinery by reducing friction and preventing corrosion.

Brands like Wolf’s Head and AtomLube offer greases formulated with special additives to shield bearings and chassis components from rust and wear, even under tough conditions. These additives may also affect the grease’s color and smell, but their main job is to boost performance and durability.

Using grease without a proper additive package can lead to early equipment failure caused by pitting, oxidation, and inadequate protection. Selecting the right grease helps keep your machines running smoothly and lasting longer.

NLGI Grade and Application Suitability

The NLGI grade measures grease thickness, ranging from 000 (fluid) to 6 (solid). Most grease guns work best with NLGI #2 grease, which strikes a balance between easy pumping and staying in place during use.

Grades lower than #2 flow well but may not hold up under pressure, risking grease loss. Higher grades resist movement better but can clog grease guns and make application tough. Brands like AtomLube and LubriMatic offer #2 grade greases designed for demanding tasks and heavy-duty gear.

Choosing the right NLGI grade for your equipment and grease gun helps maintain steady lubrication. Using the wrong grade might cause grease starvation or leaks, which can lead to increased wear and tougher maintenance down the line.

Frequently Asked Questions

What is the difference between lithium and synthetic greases for grease guns?

Lithium greases use lithium soap as a thickener, offering a balance of water resistance, adhesion, and temperature tolerance suited for general heavy-duty tasks. Synthetic greases employ advanced base oils and thickeners to maintain performance at very high temperatures and pressures.

For example, Slip2000’s synthetic formula withstands up to 750°F, far exceeding typical lithium complex greases like Wolf’s Head which max out at 375°F. Synthetics also resist oxidation better.

Choosing synthetic grease is ideal for extreme heat or precision applications, while lithium greases serve well for general industrial, automotive, and agricultural use. Avoid mixing these types without confirming compatibility to prevent compound breakdown.

Why does grease tackiness matter for high-pressure applications?

Tackiness describes the grease’s ability to stick to metal surfaces under load and vibration. High-pressure environments like wheel bearings and suspension parts demand grease that won’t be squeezed out or drip away.

Lucas Oil’s Red N Tacky formula is built to cling tenaciously, reducing re-lubrication frequency. Without tackiness, grease can wash out or leak, leaving components exposed to wear and corrosion.

When applying grease, always check for tackiness especially in wet or high-impact areas. Low-tack greases can create maintenance headaches and unexpected failures.

Is a thicker NLGI grade always better for grease guns?

NLGI grade indicates consistency rather than quality. While thicker grades (higher NLGI numbers) resist displacing under load, they may be too stiff to pump through standard grease guns efficiently.

NLGI #2 greases strike the best balance for most grease gun uses, offering good flow and staying power. AtomLube and LubriMatic products use this grade for multi-purpose applications.

Using a grease that’s too thick may clog fittings and cause uneven lubrication, while too thin grease can leak away quickly. Match the grade to your grease gun and equipment specifications for best results.

Can I use gun grease for other machinery lubrication?

Gun greases designed for firearms, like Birchwood Casey’s Long-Lasting Gun Grease, focus on rust protection and controlled film thickness, which might differ from heavy-duty automotive or industrial greases.

While some gun greases provide excellent corrosion resistance, they may lack extreme pressure additives or temperature range needed for engines or heavy machinery.

Use specialized grease formulated for the target application. Mixing types without checking compatibility risks poor lubrication and damage. Always verify manufacturer recommendations before substitution.

How do additives improve grease performance?

Additives enhance grease by providing anti-wear, extreme pressure protection, corrosion resistance, and oxidation stability. They directly protect metal surfaces against friction, heat, and moisture damage.

Wolf’s Head and AtomLube greases include EP additives that form protective films under heavy loads, preventing pitting and metal-to-metal contact. Rust inhibitors slow corrosion from moisture exposure.

Choosing grease without adequate additives leads to faster degradation and equipment failure. For demanding conditions, prioritize greases with robust additive packages.

Choosing Grease That Keeps Your Equipment Running Smoothly

Grease that fails to adhere, resist heat, or protect from corrosion causes premature wear and costly downtime. Selecting a grease with strong adhesion, wide temperature tolerance, and appropriate additives fills the gap between frequent maintenance and reliable operation.

Heavy-duty lithium complex greases like Wolf’s Head serve well for wheel bearings and chassis, while synthetic options like Slip2000 suit extreme heat or precision parts. Water-resistant formulas such as Lucas Oil’s Red N Tacky thrive in wet and harsh environments.

Apply grease with compatible guns, watch temperature limits, and avoid mixing incompatible thickeners to maintain performance. Proper grease application, adherence to specs, and periodic inspection are key to extending equipment life and reducing unexpected failures.

Last update on 2026-04-02 / Affiliate links / Images from Amazon Product Advertising API