Val Pak Generic Premier 455 Bronze Pump 5" Brass Trap Lid (V40 463) relayscontactors A check valve helps maintain A check valve helps maintain one way flow and protect the ozone side of the system from unwanted backflow supporting hydrotherapy comfort and dependable jet performance The Val Pak generic Premier 455 bronze pump 5 inch brass trap lid is designed for compatible trap assemblies where the top closure needs to be replaced with a sturdier Trap lids are useful because they affect both the sealing integrity of the basket area and the confidence the user has every time the lid is removed and reinstalled for service