RJ11 / RJ12: Used for standard telephone and landline cables.
Detachable Two-Piece Design: Features a Master unit and a detachable Remote unit. This lets you test cables even if the two ends are located in completely different rooms or far apart.
Power Source: Operates using a single 9V PP3 Battery
Speed Switch: Contains an ON / OFF / S toggle switch. The "ON" position scans at normal speed, while the "S" position runs a Slow automated scan to make tracking individual indicator lights easier.