Model "D" Pressure Reducing Regulator, Tfe Gaskets; 1/2" Size; Lcc Body & Spring Chamber; S7 Trim: 316SST With Virgin Teflon (V-Tfe) Seat,Fluorocarbon Elastomer;(Fkm) Diaphragm; Npt Screwed; 10-40 PSIG Range Spring; Opt-4: Stabilizer (Recommended For Gaseous Service Only); Standard: Opt-25: 1/8" Npt Spring Chamber Vent Tap