Ultra-wide band radar technology: detects objects up to 4-3/4 in in multiple materials Calibration-free: ready to use instantly with no setup required Spot detection: instantly locates objects on walls, floors, or panels Multiple modes: drywall, universal, and concrete detection for metals, wood, wiring, and pipes Illuminated display: color-coded lights and arrows for easy object identification D-TECT120 features Spot Detection technology that can detect objects instantly when placed on a wall, panel or floor. Since the Bosch D-TECT120 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.