Features:The longdistance linetracking function can be easily tested in the face of messy and long network cables.With the detection functions of network cable line sequence, line voltage, line short circuit, etc.Volume adjustment function, in a noisy environment, if the sound of the speaker is not evident, the volume can be adjusted up.Lighting function, the receiver is equipped with brightness LED light, and lowlight environment auxiliary lighting work.It is a necessary testing tool for telecommunication engineering, wiring engineering and network maintenance person.