Model "DA1" Pressure Reducing Regulator (Series I); Body Size 1-1/4",Standard Diaphragm Construction; Sales Kit A; Ductile Iron Body & Spring Chamber; 17-4ph SST Trim, 316l SST Cage, Pa Seat, Nbr Diaphragm,;Nbr Static Seal, O-Ring Dynamic Seal; Opt-56: Special Cleaning Per Spec #S-1542