Model CA-2 Rev A Back Pressure Regulator; 1/2" Line Size, Angle Design, Side Inlet-Bottom Outlet; Stainless Steel Body With Stainless Steel Spring Chamber; S40G Trim: 303 Stainless Steel Metal Seat, Gylon Diaphragm, NACE Construction; NPT End Connections; 30-50 PSIG Range Spring; OPT-40: Construction Per NACE Standard MR0175