Model "D" Pressure Reducing Regulator,Graphite/Nbr Gaskets; 1/2" Size; Wcb Body,Cast Iron Spring Chamber; Sk Trim: 316SST With Fluorocarbon Elastomer Seat & Diaphragm; Opt-30: 150 Lb Raised Face Flanges; 10-40 PSIG Range Spring; Opt-4: Stabilizer (Recommended For Gaseous Service Only); Standard: Opt-25: 1/8" Npt Spring Chamber Vent Tap