Mastech MS6812 Phone Telephone Line Cord Tracker, Network Line Cable TesterThe Mastech MS6812 phone telephone line cord tracker network line cable tester is designed to identify and trace wires or cables in a bunch without damaging the insulation. For telephone line, it can identify various states of the line, and make it more convenient to install, debug, and maintain. Detect continuity of the cables or wires without damaging the insulation Track the cables or wires, and diagnose the break point. A professional & safe tool