The 1/4"-1/2" Rubber Repair Kit is compatible with the 1/4”-1/2” Model 975XL and 975XL2 Reduced Pressure Principle Backflow Preventer. This Repair Kit includes all rubber components for checks and relief, including two Cover O-Rings, two Seal Rings, one Relief Valve Seal Ring, one Relief Valve Diaphragm, and one Relief Valve Steam O-Ring. 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.