The Check Repair Kit is compatible with the 1-1/4 in-2 in Model 375 and 375XL Reduced Pressure Principle Backflow Preventer. Repair Kit components include two Ball Valve O-Rings, two Sleeve/#1 Seat O-Rings, one Seat #1, one Spring #1, one Spring Retainer #1, two Seat Bolts, two Seal Retainers, two Seal Washers, two Poppets, one #2 Seat O-Ring, one Seat #2, one Spring #2, one Spring Retainer #2, one Relief Valve Seal Washer, one Relief Valve Seal Retainer, one Relief Valve O-Ring, two Sensing Port O-Rings, one Body Relief Valve, one Seat Relief Valve, one Spring Guide Relief Valve, one Spring Relief Valve, one Diaphragm, one Plunger Relief Valve, one Plunger O-Ring, one Relief Valve Cover O-Ring, and one #1 Spacer. 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.