Model DA2 Rev E Differential Pressure Reducing Regulator; 1" Line Size, OPT-81: Full Diaphragm Support Construction; Stainless Steel Body With Stainless Steel Spring Chamber, 1/8" Petcock Vent; P9 17-4PH Stainless Steel Trim, 316L Stainless Steel Cage, PTFE Seat, Fluorosilicone Diaphragm, Fluorosilicone Static Seal, Stainless Steel/PTFE U-Cup Dynamic Seal; OPT-30: Mates WIth ASME 600 Raised Face Flanges; 10-35 PSID Range Spring; Internal Sensing; OPT-65A: 1/4" NPT Double Tapped Spring Chamber