Good FiltrationOur foam filter cartridge has a high density mesh structure that filters a wide range of impurities from the pool, it effectively removes leaves, grass, hair, slag, pine, insects and others floating materials. Dimensions: 20 x 10cm. Center hole: about 4cm. DurableThis foam filter is made of high quality sponge, which is flexible, not easily deformed, environmentally friendly and can be reused after cleaning for long life. Cost SavingReplacing filter cartridges is part of your daily pool maintenance, regular replacement of paper filter cartridges will cause increased costs and waste. Washable and reusable foam filters are an ideal alternative to disposable paper filters. There is no need to replace filter sponges frequently. Widely UsedOur washable foam filters are suitable for type A and most pool filters on the market. To keep swimming pools, aquariums, bathtubs and spas clean, we recommend that you replace them fortnightly for better filtration and to keep your pool clean.