You have to pay attention to both the food you feed and the water your fish touch. Aquarium tank water filter is a necessary device for your aquarium. This item use air pump to create water current￡? in order to get the effect of filtering and to cultivate nitro bacteria. Multifunctional aquarium filter adapts to your fresh or saltwater system´s filtration needs. It is quick and easy to install and use. This economic and effective item is very practical for household.                                    Features            New and high qualityProvides biological filtration to the aquarium￡? helps to stable water qualityIncrease the oxygen solubilityWorking noiselesslyAdhere smooth surface with suction cupWater inlet hole diameter: approx 18mm                                                            Specifications            Fit for: 30cm / 11.81" AquariumDimensions: (5.71 x 5.5 x 1.77)" / (14.5 x 14 x 4.5)cm (L x W x H)Weight: 2.89oz / 82gColor: BlackWater Inlet Hole Diameter: Approx. 18mmModel: XY-2831                                                            Package Includes            1 x Biochemical filter2 x Sponge1 x Suction cup