Real Fancy's pool & spa filter is dedicated to bringing purer and cleaner water to your pool. You can experience the joy of being in the water with more peace of mind. Replacement Filter. The PRB35-in hot tub filter is compatible with Unicel C-4335, Filbur FC-2385, Guardian 409-219, Aladdin 13501, SD-00198, 03FIL1300, 17-2482, 25393, 303557, 817-3501, R173431. All manufacturers' names and part numbers are used for compatibility information only. Dimensions. Length: 9-1/4" ; Outside Diameter: 4-15/16" ; Top /Bottom Opening: 2-1/8”; Filtration Area: 35 sq. ft. The hot tub filter has ultra-high water filtration capacity. It can effectively remove hair, leaves, dust, sediment, sand, and other fine particles, easily remove debris, and always keep the water clean. The C-4335 hot tub filter is washable and reusable. Simply remove and rinse with water, and the cleaned filter will be a new one. It is recommended to clean the filter every two weeks to fully utilize its performance.