Forged brass body and bonnet - Easy-to-read single scale 21/2" gauges - 31/4" stainless steel diaphragm - Heavy duty mechanical stem type seat and nozzle assembly with removable back plug for ease of seat service - Delrin bushing for smooth flow adjustment - Fine mesh filter screen between inlet and seat - Pressure relief device for low pressure gauge protection only CGA INLET / 510 OUTLET CONNECTION / “B” (LH) 9/16"-18(M) DEL. PSIG / 2-15 REPLACEMENT 21/2" GAUGES / G22; 30 PSI (RL) G21; 400 PSI