Our COMSEC III is the only patented technology that works with the telephone company exchange. One the COMSECIII is attached to your telephone line it continuously detects the slighest signal from you phone to the telephone company. The COMSEC III scans the line before, during and after every call, when the electrical signature pattern changes the LED will flash.

More Telephone Line Analyzers. Also see our selecton of Covert Surveillance Camera