Model "SA4" Do-All Pressure Loaded Reducing Regulator (Series Iv); Body Size 2", Standard Diaphragm Construction; Bar Stock 316l SST Body & Topworks; 316lSST Plug & Cage, 17-7ph SST Diaphragm; Polyall Seat,;(Ffkm) O-Ring Static Seal, Tfe U-Cup W/SST Energizer Dynamic Seal; Tube End Bw Connections; No Range Spring, Pressure Loaded; Internal Sensing, 2-7 PSIG Lower Spring; High Purity Electro Polish To 10ra Avg. Finish, Clean To Spec;#S-1662