2" Cartridge Filter Bypass Assembly Waterways 600-10402 Bypass Valve Waterway filter internal 2" bypass valve. Part has a spring loaded flap and is inside the bottom of the filter canister. In some filter canisters this part can be replaced by accessing it from the top if the manufacturer did not glue it in. In applications were the manufacturer glued it in the plumbing line at the bottom on the side were the valve is would need to be cut for access. Fits: Waterway top load filter, Waterway Dyna Flo top