The Model 542SP Inductive/Sensing Speaker Probe and the Model 541TG Tone Generator/Sender are compatible with each other and similar devices sending or sensing tones. Designed for moves, adds and changes to telephones, LANs, security systems, audio/visual systems, the devices provide cable identification and connector tracing. The Model 542SP probe detects tones and provides an audible signal to inform the user of the correct wire carrying the tone signal. An LED provides a visual indication for the correct wire. The Model 541TG tone generator sends an alternating frequency warble signal for detection by the speaker probe. An RJ11 connector for quick plug-in to standard telephone jacks, data communications RJ45 jacks and a pair of alligator clips for quick attachment to any wire pair are provided. An LED indicates continuity and warns users of an active circuit.