SUNSUN HW-303A external canister filter is ideal for tanks up to 350 liter aquarium. The SunSun HW-303A includes filter pads, hoses and all the parts you need to get started. The media trays allow you to add other filtration media such as activated carbons, ceramic rings or bio-balls (additional can be purchase in separate listing) to achieve excellent mechanical, chemical, and biological filtration. The HW-303 canister filter also has a convenient self-priming pump that eliminates the need for manual siphoning.