Model "P4", Balanced Trim, Single Stage Pressure Reducing Regulator; 1/2" Size, Cv'=.60; 316l SST Body, 316l SST Spring Chamber; 302 SST W/Tefzel Ring Diaphragm,Tfe Seat,316l SST Seat Retainer,;316l SST Poppet,Inconel X-750 Poppet Spring,Viton/Tfe Back-Up Ring;Port Configuration "B"; Fnpt End Connection; 2-100 PSIG Range Spring; 0-160 PSIG Outlet Gauge; No Inlet Gauge; Opt-56: Special Clean Per Spec #S-1542