The Eheim Automatic Feeder contains an exclusive ventilation system which ensures that the food stored within the chamber remains dry. The feeder electronically controlled and can be programmed for up to 4 daily feeding cycles with a choice between single or double rations. It also includes a manual feed button and an LCD clock. The unit is battery operated (included) and incorporates a warning system to inform you when the batteries require changing. The Eheim Automatic Feeder can hold 100ml of flake and pellet foods. Can be mounted on the top of your aquarium hood.