Detects presence of water and rapid changes in temperature Built-in accelerometer detects tilt of more than 15 degrees Sounds siren, flashes LED, and sends alert to network when triggered Powered by battery Built-in range tester indicates wireless signal strength "Z-Wave Plus" certified for wide compatibility The FIBARO Z-Wave Flood Sensor offers a simple, yet versatile design for easy monitoring of any location. The single-piece unit senses conditions through three tiny gold metal probes on its bottom. These high-sensitivity probes can push into the unit, allowing the sensor to sit on an uneven surface. The sensor is also difficult to submerge, so if the monitored area floods with water, the unit will float and continue to report an alarm.