The Bosch GMS 120 hidden wiring detector is an easy-to-use, professional detector that avoids damage to electrical wiring or other hidden communications in walls, floors, supporting structures. The light indication, duplicated by a sound signal, will very accurately indicate the location of metal pipes and live wires. Conveniently located hole for marking the drilling location will facilitate the search process. The screen is backlit, which makes it possible to work even in rooms with low light.