Model BQ Rev A Back Pressure Regulator, OPT-45: PTFE Gaskets; 1/4" Inlets,1/2" Outlet; Sales Kit A; Stainless Steel Body With Stainless Steel Spring Chamber; S36 Trim: 316 Stainless Steel With PTFE Seat, 302 Stainless Steel Diaphragm; 65-150 PSIG Range Spring