The CT20 is an electronic instrument designed for electricians, alarm installers, cable installers, and others who need to regularly check circuits for continuity as well as identify cables and wires. It enables a single person to rapidly identify and name two cables, even if the wire ends are in separate rooms. It can support test wire lengths of up to 10,000 feet (3,000 meters), with a minimum gauge of 26. The CT20's Remote Continuity mode enables the user to assess continuity and identify two or more cables/wires concurrently.