Model "DA4" Pressure Loaded Reducing Regulator (Series IV)-PLPRV; Body Size 3",Standard Diaphragm Construction; Sales Kit A; Bronze Body & Loading Chamber; Monel M Trim, Pa Seat, Fk Diaphragm;Fk Static Seal, Tfe Cap W/Fk Energizer Dynamic Seal, Gftfe Wiper; Opt-55: Cleaned For Oxygen Service Per Spec #S-1134