Grease Control Valve Features Boosts Line Pressures Built In Relief Valve for Releasing High Greasing Pressure Enabling Easy Disconnect of the Grease Coupler from the Zerk Fitting For Use With Air Operated Grease Pumps For Volume Greasing Applications On Shop Floor And Garages Includes Extension Fitted with Coupler without Ball Check Pressure Relief Valve Max Operating Pressure 10 000 psi Inlet Size 1/4 in