The Check Repair Kit is compatible with the 1-1/4”-2” Model 350 and 350XL Double Check Backflow Preventer. Repair Kit components include two Ball Valve O-Rings, two Sleeve/#1 Seat O-Rings, one Seat #1, one Spring Retainer #1, two Seat Bolts, two Seal Retainers, two Seal Washers, two Poppets, one #2 Seat O-Ring, one Seat #2, two Springs, and one Spring Retainer #2. Repair Kits are sold as accessories for quick and simple repair needs, providing long-lasting protection from backsiphonage and backpressure of polluted water into the water supply.