Model D Rev D Pressure Reducing Regulator For General Service; 1/2" Line Size; Carbon Steel Body And Spring Chamber; S1 Trim: 316 Stainless Steel Metal Seat With 302 Stainless Steel Diaphragm; Mates With ASME 300 Flanged End Connections; 70-150 PSI Range Spring; Opt-4: Piston Stabilizer For Gaseous Service; Polyethylene Vented Spring Chamber Plug