Model HP Rev A Pressure Reducing Regulator, PTFE/FKM Gaskets (Opt-45); 1-1/2" Line Size; Sales Kit B; Stainless Steel Body With Stainless Steel Spring Chamber; S3Y Trim: 316 Stainless Steel With Nylon Seat, Neoprene (BC) Diaphragm; OPT-58: Cleaned For Hydrogen Service Per Cashco Specification S-1821