INTEX Filter Cartridge Type "A" For Swimming Pools [Pack of 2Pcs]Type A Filter Cartridge Intex filter cartridges are made from Dacron material. They are easy to clean and to replace when necessary, usually after about two weeks. Look for the large A on the package to make sure you are getting the right size for your filter. For smaller pumps: 530 gallon per hour 1,500 gallon per hour Fits pumps with both Type A and Type C filters For filter pump item numbers: 58603, 58604, 56637, 56638, 56635, 56636 Replace filter