Model 6987 Rev A Back Pressure Regulator, Aramid/SBR Gaskets; 1/2" Line Size; Sales Kit A; Carbon Steel Body With Carbon Steel Spring Chamber; S1 Trim: 316 Stainless Steel Metal Seat, 302 Stainless Steel Diaphragm; 500-1050 PSIG Range Spring; OPT-1: Closing Cap