This convenient Seat Repair Kit (#1 and #2 with O-Rings) is compatible with the 3/4”-1” Model 975XL and 975XL2 Reduced Pressure Principle Backflow Preventers. Repair Kit components include two Check Seat O-Rings, two Check Seats, one Relief Valve Seat O-Ring, and one Relief Valve Seat. The accessories within the kit allow you to speed up repairs, while lowering maintenance costs and extending the product life. The Zurn Wilkins portfolio offers long-lasting protection from backsiphonage and backpressure of contaminated water into the potable water supply.