This products is a filter. It can make good water circulation and filter the dirt in the cylinder to keep the water clean, but also the water to bring a large number of oxygen into water, the oxygen will dissolve in the water, add the oxygen content of the water quickly, and maintain a good ecological environment of the aquarium tank. Features - Color: Black. - Material: Sponge. - Size: 12.00X5.00X5.00cm;/4.72X1.97X1.97in; - Easy to install ,only fill up water and plug in and easy to maintain. - High efficiency filtration, waterfall design flow,it has a good filtering,effective filtration of impurities in water, making sure transparent and clear water. - Provides both mechanical and biological filtration, works great without noise - Cylinder wall holder, adjust the distance between the filter and the fish tank. - Suitable for fresh and sealtwater, with biochemical, physical filtration and aeration function. Package list: 1 x Aquarium Sponge Filter