Give your Bestway pool its best performance by using the Bestway Filter Cartridge Type III/A 6-Pack. It is recommended you change the filter regularly so you can filter the water in your pool and keep it attractive and refreshing all season. The 6 replacement cartridges work for your Flow Clear 530, 800, 1,300, or 1,500 gallon-per-hour filter pump. The model number for this replacement filter cartridge is 58012E. You can use it with any pool filter that needs a Type III or Type A filter cartridge that measures 4.2 inches in diameter and 8 inches tall. Ensure the long life of your Bestway pool and filter pump by replacing the filter regularly. For best performance, you should replace your pool filter cartridges once every 2 weeks. Providing an excellent replacement for your old or worn-out filter cartridge, the Bestway Type III/A Filter Cartridge Replacement 6-Pack keeps your pool clean and crystal clear for safe and relaxing swims.