High Quality Circuit Tracer - This tone generator and probe kit is made of high-quality materials, wear-resistant, corrosion-resistant. The gain is normal 30dB, the input impedance is nominal 100M Ohm. Note: the cable toner tracer needs two 9V batteries(NOT INCLUDED). Accurate & Easy - With optional continuous or adjustable generator, this cable tester toner is simple to use, makes finding the exact line SIMPLE and the test results are accurate. One button operation, very handy and usefull when your working alone. Clip and trace, 1 second to identify cables. Convenient to carry and storage the tester with carrying bag, and protect it from demage, makes it durable. Powerful & Professional - When used in conjunction with any tone generator, professional wire toner probe kit with adjustable volume is designed to identify and trace wires or cables within a group without damaging the insulation. For non-terminal cables, clamp mode can be used for direct measurement, as well as for telephone and network line measurement. Safety in Use - Tone tracer has spring-loaded ON/OFF button; adjustable volume sensitivity control; recessed terminal ports for handset connection; resistive plastic carbon-fiber tip prevents accidental shorts when probing wires. Insulation probe and built-in loudspeaker can effectively avoid short circuits of conductor and make it safer to use. Widely Application - This wire tracker are widely used in the maintenance of cables and wires. The measurement area includes line tracking, short circuit test, clear/busy/ringing identification. Selectable continuous or variable tone generator.Essential tool for electricians.