Warns of leaks and overflows in reservoirs, aquariums or anywhere there is a potential for leaks Alerts user within hearing range that water has reached desired level when used to monitor the filling of pools, reservoirs, aquariums and more Sensor and alarm can be placed up to 6 feet apart Loud 85 dB (decibel buzzer). Sounds for up to 3 days Uses 9 volt battery (sold separately) Suction cup side for mounting directly to side of sump