Material: Cotton Weight: 200 grams (about 40 pieces) Type: filter ball Diameter: 4 cm describe: Filter balls are the next generation filter material for swimming pools and are the perfect alternative to traditional sand. The fiber balls are made of polyethylene. In addition to minimal bulk and weight, the blend of fibers ensures an excellent level of particulate filtration. Unlike sand, it does not harden or clump during application. Easy to handle due to light weight. Will not deteriorate or damage seals. Resist pool chemicals. feature: It has the characteristics of light weight and high strength. It is durable and can help you clean your swimming pool. Provides excellent filtering. Has high dirt absorption capacity. They are lighter and more efficient than traditional filter media. They are easy to handle and there is no more sand in the pool. Usage Scenario: Ideal for summer pool sand filters and other water filters, the clear water makes swimming more for you and your kids. There is no sand in the pool, which is lighter and more efficient than traditional sand filters.