Aquarium Internal Filter, Submersible Power Filter With Adjustable Waterflow, Aeration System With Sponge Filter For Fish Tanks Product Size: 300l: 39*36.5*124mm600l: 46*42*134mm1000l: 55*45*154mmColour: Blackmaterial: plasticPlug: round plug (European plug)1.AQUARIUM FILTER WORKING PRINCIPL: Dirty water enters from the filter side; The water will first pass through the 3 layers of filter plates; Then water passes through the sponge filter box again; Clean water enters the filter inside, Then by water pump flows out through front outlet or rotatable outlet tap.2.WATER CHANGE FUNCTION:Our Innovative water exchange design allows for quick and easy water changes. Rotate the outlet tap to change the water out of the tank by the included hose . But only part of the water can be replaced. fish tank filter meets the scientific fish farming, all the water will not be pumped away, allowing the fish to adapt.3.LANDSCAPING & OXYGENATION: Pull out the outlet tap; Remove the top cover; Take out the small accessories; Install back cover and outlet tube; Install the fountain accessory head on the water change tube. After plugging in the power, aquarium filter will be an effect similar to a small fountain. The flow of water will also increase dissolved oxygen in the aquarium.4.UNIQUE DESIGN: This water change filter pump is the latest design. In addition to the powerful filtering function to bring you a clean and clear fish tank, its unique rotating outlet tap can meet your water change function needs, fish tank filter is multi-purpose. The additional small outlet tap plug create a small fountain effect in the fish tank, adding visual enjoyment while filtering.