Bosch DMD4K Digital Multi-Detector Kit Multi-Functional Detection of ferrous and non-ferrous metals (rebar, studs, and pipes), wood studs, and live wiring Deep Metal Detection Capability - Detects steel up to 4-Inch deep, even in concrete Zoom Feature in Metal Mode. Enhanced precision in detecting small objects, locating centers of large objects, and distinguishing between close objects Informative LCD Display indicates mode, detection strength and more Illuminated Ring around marking hole changes from green to red to indicate detection and Audible Detection Signal. Easily switches on and off