Sends a loud tone up to 16 km (10 miles) in most cables for locating and tracing, and checks continuity and polarity on inactive networks ABN clips easily allow access to individual wire pairs and RJ11 plug easily connects to telephone jacks--no need for adapters. Isolate individual pairs with SmartTone technology that generates 5 different tones Continuity and polarity are indicated by dual-color LEDs Tone can be located and traced by a compatible analog probe (sold separately)