Biochemical Double Sponge Filter, durable to use and easy to replace, suitable for all types of water As the water passes through the pores, the sponge will trap debris from your tank, leaving the water crystal clear. Effectively improve water quality. Cultivating the nitrifying , will give you superior biological filtration in your tank. This inter filter is noiseless and energy saving. Only requiring an air pump and airline tubing (sold separately) to work. These create numerous minute bubbles for increased oxygen flow. Betta, fry and other small will NEVER get sucked up into the filter. friendly, you can feel relieved to use it Aquarium inter filter can be used for many times, easy to clean Specification: Material: Cotton+Plastic Size (LxWxH): approx. 23x17x6cm/9.06x6.69x2.36 inches Max Tank Size: 52 Gallon (US), 44 Gallon (UK) Package Includes: 1 Piece Aquarium Filter Note: Before using the filter, soak in aquarium water for 5minutes Use aquarium water to wash filter sponge, DO NOT use hot water Since the size above is measured by hand, the size of the actual item could be slightly different from the size above. Due to the lighting effects, monitor settings, etc. There could be some slight difference in the color of the pictures and the actual item