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