SUITABLE FOR- This tool set can be used for all kinds of cable line installation, inspection and maintenance, and can assess the work of the telephone line in different states. This will prevent the cable insulation from being damaged. CONVENIENT- Establish the continuity of the cable or wires. Trace the cables or wires and diagnose the breakpoint. MULTIFUNCTION- Receive tone signal on cables or wires (telephone line). Identify working telephone line status (clearing, ringing, busy). Send single sliding tone or double tone on the cables or wires of the object. HUMANIZED DESIGN- Large rear speakers, loud sound, can also be heard in a noisy environment.Intelligence button and indicator light.Distance 3000m effective detection range. EASY TO USE- Not only rich in functions, this cable finder is also very easy to use, and it will be a good helper for you.