The grease gun coupler has an exclusive US patent. Our Grease Gun Coupler's reinforced jaws and premium ferrules ensure long lasting performance and prevent leaks even at extreme pressures of 14000 PSI.Made from premium galvanized alloy steel, this high-quality grease gun coupler can be used all day in the shop or garage and is heavier and stronger than any other grease coupler on the market.The grease gun coupler has a smooth retraction mechanism that allows one-handed operation. No need to hold while lubricating, locking the grease gun coupler allows you to operate the grease gun with both hands free.The upgraded grease gun coupler features a unique patented retraction mechanism that pulls the inner seal back and leaves the outer sleeve ring open to help position the grease fitting in blind spots.Portable Grease Gun Coupler fits all 1/8 NPT Standard Grease Guns, Mini Grease Guns, and also all DIN and SAE Grease Fittings, just replace your existing grease gun coupler. This heavy duty tool is an excellent tool for use on construction sites or auto repair shops for large machinery. It is also a great lube tool for farm tractors, plows, stump pullers, disc harrows, planters and more.