This system can give you peace of mind by alerting you of possible water leaks, even when you're not home! A water detector connected to a landline telephone provides advance notice of a problem and may help reduce the damage that water can do. Avoid or minimize damage from faulty appliances, burst pipes, sewer backups, leaky roofs, heavy rainfall, overland flooding, and more. This system doesn't require internet connectivity and has a battery backup for power failures. The sensor runs on a single 9V battery (not included). All that's required is a landline telephone connection and a plug. When the sensor detects water, a loud 105 dB alarm is triggered. A wireless signal is also sent to the control panel for quick notification. The dialler stores and calls up to 5 different telephone numbers five times each.