The Flood Alarm is a self contained electronic device to sound an alarm when its sensor is in contact with water. It operates on a 9 volt battery (included). The electronic horn alarm is set off immediately when the two exposed copper wire ends (at the sensor arm) contact water or moisture. The sensor arm can be used in a straight or bent position depending on its application. Once the battery is placed in, the Flood Alarm is always in the "on" position. No adjustment is needed to operate this device.