The 2 ½”-4” 350/375 Repair Kit is a complete rubber replacement solution for the check valves of 350, 350XL, 375, and 375XL backflow preventers. Designed for double check and reduced pressure zone assemblies, this kit restores proper sealing and operation of both the first and second check valves. Ideal for routine maintenance or targeted repairs, it helps maintain compliance with ASSE® 1015 and ASSE® 1013 standards while extending the life and reliability of the assembly.