TRIPP LITE's T012-001-K multi-function cable tester is an essential tool for cable installers or anyone working in telecom or LAN environments. It allows you to track cable, find a short or breakage in non-powered wires, and perform wire mapping on RJ45 cables, detecting shorts and open wires. Powered by included 9 V batteries in the main tester and remote probe unit, the T012-001-K can find an RJ11, RJ45, or BNC cable nestled within a group of cables. The probe unit's LED flashlight is handy for working in dark areas. Included headphones help you work in noisy environments. An adjustable volume button lets you fine-tune the tone generator.