Model "D" Pressure Reducing Regulator,Graphite/Nbr Gaskets; 3/4" Size; Wcb Body & Spring Chamber; S4n Trim: 416SST With Buna-N (Nbr) Seat,Neoprene (Bc) Diaphragm; Npt Screwed; 30-80 PSIG Range Spring; Opt-4: Stabilizer (Recommended For Gaseous Service Only)