Model "BQ" Back Pressure Relief Regulator,Tfe Gaskets (Opt-45); 3/8" Inlets,1/2" Outlet; Cf8m Body & Spring Chamber; S36 Trim: 316SST With Tfe Seat,302SST Diaphragm; Npt Screwed; 65-150 PSIG Range Spring; Opt-55: Cleaned For Oxygen Service Per Spec #S-1134