(2 PK) HAYWARD MODELS CL200 Inline Chlorinator Feeder Coupler Union O'rings (2 PK) HAYWARD MODELS CL200 Inline Chlorinator Feeder Coupler Union O'rings You get 2 of the #28 in diagram Fits Hayward Chlorinator inline feeders, Model CL200 Quality replacement O'rings by TORK Distributors