Model DA5 Rev E Back Pressure Regulator; 1/2" Line Size; Sales Kit A; Stainless Steel Body With Stainless Steel Spring Chamber; M7 Monel M Trim, Polyurethane Seat, Fluorosilicone Diaphragm, Fluorosilicone Static Seal, Stainless Steel/PTFE U-Cup Dynamic Seal; OPT-55: Cleaned For Oxygen Service Per Cashco Specification S-1134