Mallard Armory - CLX200K VITON Cover O-Ring for Hayward Automatic Chlorine Feeder Models CL200 and CL220 This is the one you have been hunting for. Manufactured, tested, packaged & sold in the U.S.A. by Mallard Armory. Mallard Armory seals are high-grade special composition chemical-resistant Viton O-rings to replace old, worn, or cracked o-rings to provide a proper seal for your pool system. Highlighted in diagram, this o-ring seals the cover to the feeder body to prevent chlorine gas leaks. One o-ring doubled over in bag is compatible with CL200 and CL220 pool and spa pumps. Manufacturer recommended high quality VITON material for resistance against harsh pool chlorine and chemicals