Over 3.5 In. of reach. Great for shielded PTO shafts, axles, harvester heads, U Joints and other recessed grease fittings. Rated to 10,000 psi! Locks on, stays on. Does not leak once locked on. Hands-free - does not pop off under pressure.Easily release from fittings with the thumb lever, even at extreme pressure. No more broken Zerks! Fits all standard Grease Guns - 1/8 NPT fitting. Fits all SAE and Metric Zerk fittings. Simply replace your existing coupler. Includes rebuild kit. Easily replace seal and jaws without replacing the coupler.