The 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. Specifications: send Tone frequency: 1.5 khz receive frequency range: 100 300 khz power supply: 6F22 (9V) receiver size: 238mm x 43mm x 26mm emitter size: 145mm x 35mm x 25mm receiver weight: 106G (including battery) emitter weight: 114G (including battery) package includes: 1 x cable Tester (including battery) 1 x Test pen 1 x manual