Model "DA4" Pressure Loaded Reducing Regulator (Series IV)-PLPRV; Body Size 2",Opt-81: Full Diaphragm Support Construction; Carbon Steel Body & Carbon Steel Loading Chamber; 17-4ph SST Trim, 316l SST Cage, Fkm Seat, Fkm Diaphragm,;Fkm Static Seal, SST/Tfe U-Cup Dynamic Seal; Npt End Connection; Lower Spring 2-5 PSIG Range; External Sensing, Standard - Flow To Open Direction