Model "DA1" Pressure Reducing Regulator (Series I); Body Size 1/2",Standard Diaphragm Construction; Super 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, Standard - Flow To Open Direction