Lock On Grease Coupler, Allows You To Lock On The Fitting With Just A Slight Push, Release With The Same Minimal Effort, Fits Most Grease Guns & Accessories, Positive Seal Prevents Leakage While Pumping Grease Up To 10,000 PSI, Once Locked On Both Hands Can Be Used To Operate The Grease Gun, Small Design Allows You Into Tighter Areas Than Other Lock On Couplers.