This is a Conrader unloader, pilot valve, check valve combination. This valve comes factory set 145-175 PSI however, it can be adjusted +/- 30-40 PSI if needed. This valve has a 3/4" Female NPT inlet and a 3/4" Female NPT outlet port. Also included is the Conrader EM-50 Muffler on the exhaust port to help silence the outgoing air. This valve features a 1/8" port for unloader or throttle control. If an unloader or throttle control is not required in your application, this port can simply be plugged.