Included with the EBPR-17-THP201 PhoneAlert Power Failure, Freeze and Flood Monitoring System, the Water Sensor Accessory (EBPR-17-THPWSA) can be added to the EBPR-17-THP202 PhoneAlert Power Failure and Freeze Monitoring System to provide the added feature of water leakage and flood detection. The water sensor plugs into the accessory jack on the EBPR-17- THP202 and can be extended up to 100 feet to monitor for unwanted water or flooding. Simply place the water sensor prongs on a floor or in a sump crock for detecting contact with water.