The Complete Poppets, Springs and Seats Repair Kit is compatible with the 1/4 in-1/2 in Model 975XL and 975XL2 Reduced Pressure Principle Backflow Preventer. Repair Kit components include two Cover O-Rings, one #2 Check Spring, one #1 Check Spring, two Poppets, two Seal Rings, two Seal Ring Retainers, two Retaining Bolts, two Check Seats, two Check Seat O-Rings, one Relief Valve Seat O-Ring, one Relief Valve Stem O-Ring, one Relief Valve Seat, one Spring, one Retaining Bolt, one Ring Retainer, one Seal Ring, one Lower Plunger, one Diaphragm, and one Upper Plunger. 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 back siphonage and backpressure of contaminated water into the potable water supply.