The Tank Boss Advanced ATO by UltraLife works as an excellent Auto Top Off, Level Safety and Leak Detection controlled by six reed float switches. These switches even allow you to easily keep track of your alarms and water levels. This system is designed to shut off your pumps, heaters and alarm you when low water levels are detected. To prevent your sump, skimmer or aquarium from overflowing, an overflow safety is available followed by a Leak Detection which will alarm you if your filter or aquarium may unexpectedly leak. This system functions on 12 volts and includes a digital timer.