Water level controller with only one sensor for nano aquariums or small aquariums with up to 55 US gal. Can be installed in a cabinet filter or directly on the aquarium edge. Scope of delivery: ready for installation with 11V power supply, low-voltage metering pump, 118 inch hose, magnet holder for up to 3/8" glass thickness and a protective cover for the sensor. PLEASE NOTE, DUE TO A SAFETY SHUT OFF AFTER 3 MINUTES MAXIMUM, THE 3152 NANO OSMOLATOR IS NOT SUITABLE FOR AQAURIUMS OVER 55 US gal.