The Hydor Ekomixo Fish Feeder is a battery operated, easily programmable automatic fish feeder.Takes 2 AA batteries, not included, and includes a low battery indicator featureSettings for once, twice, or three times a day feedingFood container is adjustable to release the desired amount at feeding timeAirline input for the use of an optional air pump to ventilate the food to prevent clumpingTimer starts when the batteries are installed