UNIVERSAL Floor Heat System LoudMouth Installation Monitor, 9 Volt Battery Included Features The LoudMouth Monitor sounds an alarm if the Heating Wire is cut or damaged, allowing for easy repair BEFORE the mat is covered with Mortar & Tile A green light to indicate GO and a Red light to indicate STOP, there's damage A very Loud Alarm Simple operation with an On/Off Switch and a TEST button Works with most radiant floor heat mats and cables. Screwdriver included for attaching mat leads 1 LoudMouth can be used to monitor up to 3 mats at once