Keep your pool water clear and clean with a Filter Cartridge (Type IV, Type B) by Bestway®. This replacement cartridge measures Ø5.6''x10''/14.2cmx25.4cm in and is designed for 2500 gallon per hour filter pumps. They are easy to clean and sift dirt and debris out of your pool with your pump. Bestway® recommends replacing them every 2 weeks for best results.