These pool filter balls are designed to replace traditional sand filter media and deliver fast, efficient water filtration. Made from 100% polyester fiber, they help trap fine particles such as pollen, dirt, and grass clippings for cleaner, clearer water. The reusable design supports hand or machine washing for easier maintenance and long-term use. They are compatible with sand, cartridge, and DE filter systems, making them a versatile option for pools, aquariums, and fish tanks.