Ideal For Unoccupied Dwellings, The Suction-Mounted Window Flasher Activates And Notifies Neighbors When The Remote Wireless Monitor Detects A Water Hazard Or Detects The Temperature Falling Below 45 Degrees F. The Flasher Functions Up To 120-Feet (It Could Even Be Left With A Neighbor) From The Monitoring Device And Operates Continuously For 24-Hours On Fully Charged Batteries. Multiple Flasher and/or Audible Alarm (Item No.EBPR-17-THP204) Detectors Can Be Linked To Monitor Multiple Locations In The Dwelling. FCC Approved. Requires One 9-Volt and Three AAA Batteries (Not Included).