Model D Rev D Pressure Reducing Regulator For General Service; 1/2" Line Size; Carbon Steel Body With Ductile Iron Spring Chamber; S2N Trim: 416 Stainless Steel Metal Seat With Neoprene (BC) Diaphragm; NPT Threaded End Connections; 30-80 PSI Range Spring; Opt-4: Piston Stabilizer For Gaseous Service; Polyethylene Vented Spring Chamber Plug