Warns person(s) of interest of the presence of operational mobile phones, ‘spy’ phones or ‘spy’ modules, located in the room where the Phone Detector has been placed. This can be an all important matter in environments where the use of mobile phones is forbidden (subject during an examination, in prisons, hospitals, etc.) and to detect these signals during confidential meetings (presence of operational ‘spy’ phones, etc.). Adjustable detecting range 5-15 meters. Powered by supplied 12 volt AC adapter or optional (external) battery.