Model D Rev D Pressure Reducing Regulator For General Service (Opt-20: Dome Loaded); 3/4" Line Size; Ductile Iron Body And Carbon Steel Loading Chamber; B2 Trim: Brass With BUNA-N (NBR) Seat And Neoprene (BC) Diaphragm; NPT Threaded End Connections; Opt-87: With 1/8" NPT Inlet And Outlet Gauge Ports And Plugs