Model "DA4" Pressure Loaded Reducing Regulator (Series IV)-PLPRV; Body Size 3",Standard Diaphragm Construction; Cf3m Body,316l SST Loading Chamber; Monel M Trim, Pa Seat, Epr Diaphragm;Epr Static Seal, Tfe Cap W/Epr Energizer Dynamic Seal, Gftfe Wiper; 300 Lb Raised Face Flanges; Lower Spring 2-5 PSIG Range; Internal Sensing, Standard - Flow To Open Direction; Opt-55: Cleaned For Oxygen Service Per Spec #S-1134