D-tect 120 features Spot Detection technology that can detect objects instantly when placed on a wall, panel or floor. Since the Bosch D-tect 120 never needs calibration, you can focus on the job without worrying about accuracy. Three modes, drywall, universal and concrete, make this the right detector for multiple jobs. Universal mode sees through more material, it sees" anything in anything." This device offers sound and a light to show user when something is detected behind a wall, panel or under flooring.