Model 31-N Rev A Low Pressure Reducing Gas Regulator; 3/4" Body Size, #2 (0.125") Orifice; Carbon Steel Body, Stainless Steel Lower Case, Carbon Steel Spring Chamber, Arrangement/Position 1, Internal Sensing Unless External Sensing Option Is Specified; S40T Trim: 316L Stainless Steel Internals, PTFE Seat, BUNA-N Diaphragm With FEP Liner, Graphite/PTFE Load Ring; OPT-30: Mates With ASME 150 Raised Face Flanges; 11.0-16.0" wc Range Spring