MODEL "DA2" DIFFERENTIAL PRESSURE REDUCING REGULATOR (SERIES II)-PDRV BODY SIZE 1/2",STANDARD DIAPHRAGM CONSTRUCTION; CARBON STEEL BODY & CARBON STEEL SPRING CHAMBER,1/8" PETCOCK VENT; 17-4PH SST TRIM, 316L SST CAGE, GF-TFE SEAT, FKM DIAPHRAGM, FKM STATIC SEAL, SST/TFE U-CUP DYNAMIC SEAL