Water level controller with only one sensor for nano aquariums or small aquariums with up to 200 liters (55 USgal.). Can be installed in a cabinet filter or directly on the aquarium edge. Scope of delivery: ready for installation with 12 V power supply, low-voltage metering pump, 3 m (118 in.) hose, magnet holder for up to 10 mm (3/8") glass thickness and a protective cover for the sensor.