Model "DA5" Back Pressure Regulator (Series V)-BPV; Body Size 1/2",Standard Diaphragm Construction; Supper Duplex SST Body / Spring Chamber; Hastelloy-C Trim, Gf-Tfe Seat, Fkm Diaphragm;Fkm Static Seal, Hastelloy-C U-Cup Dynamic Seal; Npt End Connection; 20-80 PSIG Range Spring; Internal Sensing, Reverse - Flow To Open Direction