Stop the guesswork and start tracing with professional-grade accuracy. The Extech TG20 Wire Tracer Kit is a must-have for electricians, IT technicians, and DIY enthusiasts who need to navigate the "rat's nest" of cables found in modern homes and offices. Whether you are tracking a phone line across a building or identifying a specific wire in a bundle, this kit provides the clarity and reliability you expect from a world leader in test and measurement. The kit features a powerful transmitter that injects a traceable signal into your cables and a high-sensitivity, non-contact probe to follow that signal from source to termination. With the adjustable sensitivity dial, you can filter out interference and hone in on the exact line you are searching for. For your safety and the longevity of the device, this kit is designed for use on non-energized circuits only. Misuse on live AC lines can be hazardous and may damage the equipment. From checking continuity to verifying phone line polarity (Tip/Ring), the TG20 is built for multi-functional utility. It is lightweight, rugged, and comes with everything you need—including the batteries—to solve your wiring mysteries today.