Model DA8 Rev E Differential Back Pressure Regulator; 2" Line Size, OPT-81: Full Diaphragm Support Construction; Sales Kit A; Carbon Steel Body With Carbon Steel Spring Chamber, 1/8" NPT Petcock Vent; S9 316L Stainless Steel Trim, PTFE Seat, Fluorosilicone Diaphragm, Fluorosilicone Static Seal, Stainless Steel/PTFE U-Cup Dynamic Seal;