Model DA5 Rev E Back Pressure Regulator; 1" Line Size; Sales Kit A; Stainless Steel Body With Ductile Iron Spring Chamber; T9 17-4PH Stainless Steel Trim WIth Monel Cage, PTFE Seat, Fluorosilicone Diaphragm, Fluorosilicone Static Seal, Stainless Steel/PTFE U-Cup Dynamic Seal; OPT-55: Cleaned For Oxygen Service Per Cashco Specification S-1134