Professional Wire Tracker: design to judge continuity of cables or wires, track the wires or cables and diagnose the break point within a group without damaging the insulation. Telephone Line Checker: It can identify the state in the working telephone line, Clear, Ringing, Busy. (only the transmitter can be detected). Network Cables Verifying: Plug one side of the cable into the emitter and the other side into the receiver. Select "Network" to check and verify cables working status. Tips: Send a single solid tone to the object cables or wires; Receive the tone signal on the cables or wires (telephone line). Application: Suitable for not only Ethernet LAN, RJ45 internet cable, RJ11 telephone line, but also electrical and speaker wires when connecting to alligator clip.(NOTE: make sure the wires should be in power-off status). Color:As shown Material:plastic Package Contents: 1 * MS6812 Cable Tracker Kit(Without 2x9V battery) Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.