Made in USA!! NSG1 145-175 Unloader Valve (continuous run Unloader) for gas & electric powered air compressors 145-175 factory setting. pressure can be adjusted 30-40 psi up or down 1/2" Female Pipe Thread Inlet x 1/2" Female Pipe Thread outlet. comes complete with hand unloader and muffler/silencer. 18 scfm Rating Piloted discharge check valves combine a pilot valve, a discharge valve, and a check valve into one system used to run an air compressor at a constant speed. They are used on both gas engine and electric motor compressors. Brand new!