Model DA8 Rev E Differential Back Pressure Regulator; 3" Line Size; Carbon Steel Body WIth Ductile Iron Spring Chamber, 1/8" NPT Petcock Vent; PD 17-4PH Stainless Steel Trim, 316L Stainless Steel Cage, GF-TFE Seat, Fluorocarbon Diaphragm, Fluorocarbon Static Seal, Stainless Steel/PTFE U-Cup Dynamic Seal; OPT-30: Mates With ASME 150 Raised Face Flanges; 10-40 PSID Range Spring; Large Internal Sensing; OPT-65A: 1/4" NPT Double Tapped Spring Chamber