Locking and sealingSaker grease gun coupler own an exclusive US patent.Our grease gun coupler reinforced jaws and quality sealing gasket ensure long lasting and stable performance,prevent leakage even at 14000 PSI extreme pressure. Robust Build QualityThis high quality grease gun coupler built with premium quality zinc coated alloy steelfor for all-day performance in the shop or garage,heavier and stronger than any other grease couplers on the market. One Hand OperationGrease gun coupler with smooth retraction mechanism allows one-hand operation.No need to hold while greasing,after locking the grease gun coupler,you can free your hands to operate the grease gun. Unique Design Upgraded grease gun coupler have the unique and patented Retract Mechanism pull back the inner seal and leave outer socket ring wide open,which help locating zerk fittings at blind spot. Wide ApplicationThe Saker portable grease gun coupler fits all 1/8 NPT standard grease guns, mini grease guns,It also fits all DIN and SAE grease fittings,simply replace your existing grease gun couplers.This heavy-duty tool is an excellent device to have on a construction job site or in an auto mechanic garage to use on your large machinery.It is also a great lubrication tool to have at the farm for your tractor, plow,stump puller,disc harrow,seeder,etc.