This piloted discharge check valve is a combination of a pilot valve, a pressure discharge valve, and check valve in one complete piece to make a constant run air compressor with gas engine or electric motor. This Valve will relieve the pressure the compressor is pumping out to the atmosphere through a silencer so the compressor can stay running without building pressure. Specifications: Material: Machined Brass USA MADE 1/2" Female NPT Pipe Thread Outlet To Tank 3/4" Compression Thread Side Inlet For 3/4" Copper Tubing 1/8" NPT Female Pipe Thread Port For Throttle Control Factory Set At 95 PSI Cut In & 125 PSI Cut Out Pressure Pressure Can Be Adjusted 30-40 PSI Up or Down 30 CFM Rating Equipped With A Manual Unloader Flip Valve At The Top Of The Unloader