Analog Tone and Probe is the best choice for toning and tracing wire on non-active networks, and specifi?cally for identifying individual pairs with SmartTone technology. Angled bed-of-nails clips allow easy access to individual wires, and the RJ11 connector is ideal for use on telephone jacks. The large loud speaker on the probe allows to hear through drywall, wood or other enclosures to find wires quickly and easily. Loud tones can be send up to 10 miles (16 kilometers) on most cables. Suitable for any wire identification job.