[Easy to use] This cable tester can quickly and easily find breakpoints without opening the wire cover. Audio signals are received through cables or wires (telephone lines). Tells you the status of your telephone line, such as idle, ringing or busy Safely inspects cables without disturbing cable installations Sensitivity TestThe MS6812 cable detector is equipped with a very loud horn. Even though the tester is noisy, it can trace the cable more closely and identify cable problems. Determine business phone line status (cut, ringing, busy). [High Quality] This wire tester features a sensitive sensor module capable of quickly detecting and responding to problems of the work circuit. Easily install, commission and maintain one or more telephone lines around your home or office with this high quality tracing system [Function] Robot lawn mower wire finder can check wire continuity and detect short circuit, open circuit and cross state testing. Effective detection distance of 3000 m. Simple and easy to use. [Packing list] 1 * transmitter, 1 * receiver, 1 * user manual, 2 * battery. Product description Sensitive sensor module The cable tester has a sensitive detection module that checks wire continuity and detects short circuit, open and crossover condition tests . scope Internet cafe hotel network computer room power supply maintenance monitoring network installation line engineering Does not damage insulation Cable detectors detect the passage of cables or wires without damaging the insulation. Check cable continuity. Locate cables or wires and diagnose break points.