Model "DA2" Differential Pressure Reducing Regulator (Series II)-PDRV; Body Size 1",Opt-81: Full Diaphragm Support Construction; Lcc Steel Body & Lcc Steel Spring Chamber; 17-4ph SST Trim, 316l SST Cage, V-Tfe Seat, Fk Diaphragm,;Fk Static Seal, SST/Tfe U-Cup Dynamic Seal; 600 Lb Raised Face Flanges; 1-10 PSId Range Spring; Internal Sensing, Standard - Flow To Open Direction; Opt-65a: Double Tapped Spring Chamber,1/4" Npt