This listing is for one new 95-125 PSI piloted discharge check valve / unloader valve combo with a 1/2" male flare fitting for the air inlet port. This check valve combo is made by Conrader in the U.S.A. This is an NS series valve. This valve is usually used on compressors that pump less than 20 CFM, and can be used on gas or electric air compressors. This valve is equipped with an in line check valve and attached to the side is a built in piloted unloader valve set 95-125 PSI. There is a built in muffler in the exhaust air port to quite down the unloaded air that is released once the compressor reaches 125 PSI. On the side of the valve there is a 1/8" Female NPT port that controls the throttle on a gas engine and/or unloader valves on some pumps.