The Pro3000 Analog Tone and Probe is the best choice for toning and tracing wires on non-active networks, specifically 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 you to find wires quickly and easily behind drywall, wood, etc. Case attached.