Model "BQ" Back Pressure Relief Regulator,Graphite/Nbr Gaskets; 1/2" Inlets,1/2" Outlet; Wcb Body,Cf8m Spring Chamber; Sales Kit B; S36 Trim: 316SST With Tfe Seat,302SST Diaphragm; 5-15 PSIG Range Spring; Opt-1+6: Differental Construction With Closing Cap