The Triplett CTX590A ProTone Wire Locator Kit comprises a tone generator and a probe, both useful for tracking down shorts in circuits, for testing connections, and for locating wires. Its inductive probe senses a tone sent to the wires with the included tone generator, which offers RJ11, RJ45, and insulated alligator clip connections. Clips for all these connections are supplied with the unit. \r\n\r\nA red/green LED on the probe shows you the continuity, voltage, and polarity of the signal you're tracing. The probe also offers a sensitivity control. It ships with the aforementioned clips, the 9V batteries needed to power the probe and tone generator, and a case.