Interstate Pneumatics 3/4 inch Male NPT Jack Hammer Universal Twist Lock Coupling. Universal design provides quick, easy and effective coupling of air hose. Ideal for Jack Hammer and other industrial applications. With the universal head, any fittings within that range can be connected regardless of hose shank or thread size. Includes Safety Pin and Rubber Gasket, also sold individually. Maximum working pressure 200 PSI. Note: The use of an Interstate Pneumatics Jack Hammer Hose Safety Cable is recommended to assure that if couplings are accidentally disconnected they will not fly and hurt someone. Only one Jack Hammer Hose Safety Cable is required for each universal coupling set - two couplers coupled together. The pin guarantees the fittings are properly connected as pin will not go through holes in mating flanges until couplings are locked in place.