Model DA6 Rev E Pressure Loaded Back Pressure Regulator; 1/2" Line Size, OPT-81: Full Diaphragm Support Construction; Sales Kit A; Stainless Steel Body With Stainless Steel Loading Chamber; PD 17-4PH Stainless Steel Trim, 316L Stainless Steel Cage, GF-TFE Seat, Fluorocarbon Diaphragm, Fluorocarbon Static Seal, Stainless Steel/PTFE U-Cup Dynamic Seal;