This Klein Tools VDV500-063 tone generator helps with wire identification, wire tracing and wire pair identification. The tone generator provides five distinct tones for exact pair identification and features angled bed-of-nails (ABN) clips to securely attach to wires. An RJ11 plug easily connects to telephone or RJ45 data jacks to tone wire pair. Check for continuity and polarity with results indicated by clearly labeled, easy-to-read LEDs.