Product Description: Material:Cotton Weight:200g/500g/700g (Optional) Type:Filter Ball Quantity:1 Bag Diameter:0.4cm/0.16" (Approx.) Package Included: 1 Pack x Filter Balls Notes: 1.Transition:1cm=10mm=0.39inch,1g=0.001kg=0.0022lb=0.035oz. 2.Due to the screen difference,the color may be a little different from what you expect,please allow it. Pool filter media is designed to replace the filter sand for pool sand filters Perfect for summer pool sand filter and other water filters, clear water makes you and your children enjoy swimming more. No sand in the pool, lighter and more efficient than traditional filter sand These filter balls are made of cotton material. It has the advantages of high filtration strength, fast filtration speed, long service life, reusable, good elasticity, and low loss Unlike sand, the filter ball does not block your filter and requires less backwash for maintenance purposes. Premium filter media extends filter life and is a perfect replacement for filter sand, filter glass and other media With proper care and handling, the swimming pool balls can last for several seasons. These reusable filter balls are machine wash friendly and you can clean them whenever needed