This item is a Fish Tank Filter Resin, made of , very sturdy and durable to use. This product is suitable for many occasions, the size is fit for most fish tanks. Suitable for fish tank and aquarium, and bring much convenience to you. Made of high grade material, it doesn’t interfere with your fish tank's other accessories. Features -Color:White -Material:Protein Cotton -Size(250ml):8.50X8.50X6.50cm/3.34X3.34X2.55in -Suitable for water filters to provide a fresh and healthy environment for fish in the fish tank.Fish Tank -Filter Resin has the functions of yellow water, anti-algal , odor and adsorbing nitrate -Fish Tank Filter Resin is washable and reusable, it will provide the lasting purification for your fish tank. - improve water quality, inhibit the growth of . Can be reused without harming fish. -It is easy to , and you can use aquarium filter for a long time. It also can help you . Package list: 1 x Bottle of Fish Tank Filter Resin