Model BQ Rev A Back Pressure Regulator, Graphite/NBR Gaskets; 1/2" Inlets,1/2" Outlet; Ductile Iron Body With Ductile Iron Spring Chamber; S1 Trim: 316 Stainless Steel With Metal Seat, 302 Stainless Steel Diaphragm; NPT End Connections; 65-150 PSIG Range Spring