Intex Filter Cartridge "B". Filter cartridge is approximately 8 inches by 4.25 inches in diameter. Suitable for use with 18ft - 24ft Intex Easy Set Pools and Intex Frame Pools. The B filter Cartridge is easy to replace and install, simply loosen the top screw lid of the pump, raise the pump above water level and remove the filter cartridge. To make your new filter cartridge last as long as possible clean it out regularly, this can be done in a bucket with warm water and Filter Cartridge cleaner, never use a pressure washer or any hose with a high pressure outlet as this will damage the filter.