Model "POSR-1" Pilot Operated Press Reducing Reg,Graphite/Nbr Gaskets; 1/2" Size; Main Valve-Ductile Iron Body & Load Chamber,Pilot Valve-Ductile Iron;Body & Cast Iron Spring Chamber; S2 Hard Trim: Main Valve-416SST Plug, Pilot Valve-416SST,302SST;Diaphragm; Npt Screwed; No Range Spring - Opt-20: Dome - Pressure Loaded