Model D Rev D Pressure Reducing Regulator For General Service; 1/2" Line Size; Carbon Steel Body And Spring Chamber; S36 Trim: 316 Stainless Steel With PTFE Seat With 302 Stainless Steel Diaphragm; NPT Threaded End Connections; 10-40 PSI Range Spring; Opt-4: Piston Stabilizer For Gaseous Service; Polyethylene Vented Spring Chamber Plug