[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 phone line, such as idle, ringing or busy Safely inspects cables without disturbing cable installations 【Sensitivity Test】The 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 the status of the business telephone line (off, ringing, busy).[High Quality] This wire tester has a sensitive sensor module that can quickly detect and respond to work circuit problems.Easily install, commission and maintain one or more telephone lines around your home or office with this high quality tracing system [High Quality] This wire tester has a sensitive sensor module that can quickly detect and respond to work circuit problems.Easily install, commission and maintain one or more telephone lines around your home or office with this high quality tracing system [Function] The robot lawn mower wire detector can check wire continuity and detect short circuit, open circuit and cross state test.Effective detection distance of 3000 m.Simple and easy to use. [Packing list] 1*transmitter, 1*receiver, 1*user manual, 2*battery.