THIRDREALITY Zigbee Water Leak Sensor. I got it off amazon $20 works great with ZB2MQTT I have it under my AC unit in the garage incase the drain gets plugged and condensation goes crazy. It beeps loudly when it detects water so if something is up with your HA or zigbee network, it still alerts someone. I would buy another one, prime shipping and not too expensive.
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