Used for tracking Coaxial cables or checking cables for short circuits. It comes with a built-in red LED light that will turn red if there is a short in the cable; it also comes with an audible tone speaker for tone verification. Simply connect the transmitting end of the toner to the outlet you wish to track, and apply the tone adaptor to the group of cables. When the right cable is connected, it beeps. Features: -- An audio tone identifies line carrying signal -- LED indicator checks circuit integrity in new and installed cables -- Right-angled male push-on connector for fast/easy use -- Easy to hold, rugged anodized body -- 4" in length; easy to hold; very portable. -- Rugged anodized all-metal body construction for reliability -- Using AAA battery