Sonin 00702 Water Alarm with Dual Sensors Dual Remote Sensor will expand the area of coverage to detect the presence of water by placing 2 sensors up to 12 feet from each other 85 db buzzer sounds for up to 3 days to alert user of potential water problems. Low battery signal alerts user when battery needs replacing Test button allows you to periodically activate to ensure unit is working. Sensors can be placed flat or suction cupped and alarm unit can be table, shelf or wall mounted.