Model "DA1" Pressure Reducing Regulator (Series I); Body Size 1",Standard Diaphragm Construction; Carbon Steel Body & Carbon Steel Spring Chamber; 17-4ph SST Trim, 316l SST Cage, Pa Seat, Nbr Diaphragm,;Nbr Static Seal, Tfe Cap W/Nbr Energizer Dynamic Seal, Gftfe Wiper; 150 Lb Raised Face Flanges; 20-80 PSIG Range Spring; Internal Sensing, Standard - Flow To Open Direction; Opt-25s: Screen For Spring Chamber Vent