Aqueon Betta Filters are air operated filters that improve water quality in small betta habitats, such as bowls and aquariums up to 3 gallons. The replaceable carbon and sponge cartridge keeps water cleaner and clearer. Each filter comes with a decoration (natural plant or volcano) to conceal the filter, along with accessories for operation (airline tubing, airline tubing suction cups, air adjustment valve and check valve). An air pump (not included) is required to operate the betta filters. The Aqueon QuietFlow Air Pump 10 (sold separately) is suggested.