The Fluke Networks Pro3000 Analog Tone Generator with ABN clips and an RJ11 plug connects to inactive networks, sending a loud tone up to 16 km (10 miles) in most cables and providing five distinct cadences for isolating individual wire pairs. It also checks continuity and polarity, which are indicated by dual-color LEDs - -red for continuity, and red and green for polarity of a DC-powered wire pair. The ABN (angled bed-of-nails) clips allow access to individual wire pairs and the RJ11 plug connects to telephone jacks. The tone generator injects a tone, either constant or alternating, into a cable, and its SmartTone feature allows that tone to be modified to any of five distinct cadences for isolating individual wire pairs within a multi-pair cable. The generated tone can be located and traced by a compatible analog probe (sold separately). Additional specifications include various environmental operating conditions. Tone generators are used by network technicians to troubleshoot and maintain wires and cable in telephone and data networks.