Model "DA1" Pressure Reducing Regulator (Series I); Body Size 2",Standard Diaphragm Construction; Sales Kit A; Carbon Steel Body & Carbon Steel Spring Chamber; 17-4ph SST Plug/Cage/Piston Guide Bearing,Fluorosilicone(Fk);Diaphragm,V-Tfe Seat; Buna-N(Nbr) Static Seals,Buna-N(Nbr) O-Ring Dynamic Seal;