Model DA6 Rev E Pressure Loaded Back Pressure Regulator; 4" Line Size; Sales Kit A; Ductile Iron Body With Ductile Iron Loading Chamber; PB 17-4PH Stainless Steel Trim, 316L Stainless Steel Cage, Polyurethane Seat, Fluorocarbon Diaphragm, Fluorocarbon Static Seal, Stainless Steel/PTFE U-Cup Dynamic Seal