The Groz Air-O Grease Coupler is designed for high-pressure applications upto 7500 PSI and is recommended for use with Grease Control Valves. The coupler body and all internal parts are precisely hardened to withstand high dynamic pressures without deformation. The reversible spring steel jaws extend service life, while the integrated ball check valve prevents backflow boosting efficiency. The hexagonal nut at the end makes tightening convenient. Each coupler is 100% tested for pressure before dispatch.