1. Convenient: The filter is suitable for A-type filters that meet your needs. 2. Advanced materials: The size of the polyurethane sponge is 200 x 100mm (length x width) (approximately), and the package contains 3 pool sponge filters. 3. Convenient design: The lifespan of this foam filter is longer than. that of your ink cartridge, and it can be cleaned and reused many times. We recommend replacing the cartridge once a week. These foams are easy to clean and replace. 4. Easy to use, all you need to do is remove the filter when you hit the electrode stick. Excessive chlorination will cause the foam to burst quickly. Normal levels of chlorine and bromine sanitization are good and these foams have been tested at normal levels. 5. Perfect Use: Replacing the filter paper filter element is part of the daily maintenance of your swimming pool and replacing the filter element regularly is costly. These washable and reusable foam filters can reduce your costs. Package includes: 3 sponge filters