A Leak Sensor is used to detect broken water pipes or other leakage. When leakage is detected quick action can be taken to limit the damage. A single group address needs to be configured. You can receive notifications when the sensor detects a leak and create automations based on these notifications in the Home app. It can automatically turn off power or close a valve.
Note: This sensor is not available in Alexa. Google support for this sensor is available in the beta channel