Model D Rev D Pressure Reducing Regulator For General Service; 1" Line Size; Carbon Steel Body And Spring Chamber; S3 Trim: 316 Stainless Steel With PTFE Seat And Neoprene (BC) Diaphragm; NPT Threaded End Connections; 2-15 PSI Range Spring; Opt-4: Piston Stabilizer For Gaseous Service; Polyethylene Vented Spring Chamber Plug