This pool filter is compatible with the following brand and models: Watkins 303279(not 303263), FC-2402, Free Flow and Lifesmart Hot Tub Filter, 1 1/2" Finer Thread and some other SPA models. Note: all the manufacturers' name and brands' name are just for reference purposes only, we own an independent brand. Our filters are with even pleats to filter more effectively and reinforced end caps to perform better, as well as strong bands to hold the product in position. It can be cleaned easily and used repeatedly.