This product uses environmental high density sponge. It can absorb dirt and quickly resolve fish feces and eliminate smell in water.Features:Filtration and oxygenation functions， suitable for aquariums with the size of 10-80cm.The bio-sponge filters are designed and constructed with quality material， durable for use.It's useful for as breeding filter or as secondary filter.Can increase the solubility of oxygen in the water.Can be also used as auxiliary filter for big size aquariums after linking with oxygen pump(not included).Specifications:Color: BlackMaterial: Plastic + SpongeItem Size: 16.5 * 6 * 24.5cm / 6.5 * 2.36 * 9.6in (L * W * H)Item Weight: 67g / 2.36ozPackage Size: 30 * 22 * 7cm / 11.8 * 8.66 * 2.75in Package Weight: 143g / 5.07ozNote:Please dip the filter into the water for 5 minutes before using which let the nitrifing bacterias attach easily.As clean the filter fibers， don't use hot water or fresh water， the best cleaning effect will be achieved when original water of the aquarium.Package List:1 * Biochemical Filter2 * Sponge2 * Suction Cup