Lumax Brand Grease Coupler. For use with most hand-operated grease guns and equipment. Fits all 1/8" NPT threads. 6000 PSI (414 Bar) maximum operating pressure. Built-in spring-loaded ball check valve prevents leak, pressure loss and lubricant backup. Four hardened steel jaws for a superior seal and longer life. Precision fit. Slight pushing action snaps jaws onto fittings. Small outside diameter permits easy contact with recessed fittings. Knurled body and easy flats for easy installation and removal. Zinc-plated for maximum protection against corrosion