The Bosch GMS120-27 wall scanner provides quick, easy and accurate detection of wood and steel studs, metals and live wires behind drywall. Power flexibility helps keep the scanner up and running on the job with the option to use with the included two AA batteries or 3.7 V li-ion battery. Get clear, confident results with the intuitive user interface that displays object center indication and material identification. Easy-to-use, the device glides smoothly across the wall and the color-coded illuminated marking ring makes fast, accurate work of transferring detection results. IP54 rating and shock absorbing rubber casing help provide added durability on tough jobsites.