Product Description: Lumax Standard Grease Coupler is f or use with most hand-operated grease guns and equipment.Built-in spring-loaded ball check valve prevents leaks, pressure loss and lubricant backup. Four hardened steel jaws create a superior seal and a slight pushing action snaps jaws ontofittings. Small outside diameter allows easy contact with recessed fittings; knurled body makes foreasy installation/removal. Fits all 1/8" NPT threads. 6000 PSI (414 Bar) maximum operating pressure. Zinc-plated for maximumprotection against corrosion.