Model D Rev D Pressure Reducing Regulator For General Service; 1/2" Line Size; Bronze Body And Spring Chamber; S1 Trim: 316 Stainless Steel Metal Seat And 302 Stainless Steel Diaphragm; Opt-31: British Standard Pipe Taper Threaded End Connections; 30-80 PSI Range Spring; Polyethylene Vented Spring Chamber Plug