• Factory replacement kit
• No special tools required for servicing
• All parts are made of high quality materials
• Parts are specific to valve size

This total rubber parts kit provides all the parts necessary to repair or replace the rubber parts on a 2 1/2 to 4 inch reduced pressure zone assembly backflow preventer, model 957 and reduced pressure detector assembly backflow preventer, model 957RPDA. This kit consists of first and second check module O-rings, 2 EPDM disc elastomers, 2 e-clips, relief valve diaphragm, relief valve inlet coupler O-ring, and relief valve piston assembly.