Model 1164 Rev B Back Pressure Regulator, OPT-45: PTFE Gaskets; 1" Line Size; Sales Kit B; Bronze Body With Bronze Spring Chamber; S5 Trim: 316 Stainless Steel Trim With PTFE Seat, Phosphor Bronze Diaphragm; 70-150 PSIG Range Spring; OPT-55: Cleaned For Oxygen Service Per Cashco Specification S-1134