This tool will detect live (or dead) electricity cables, water/gas pipes and wood studs or battens. Powered by a PP3 type battery (not supplied) the red LED on the detector will stay lit together with a continuous audible sound when metal is detected. When electricity is found the red LED will flash and the audible sound will sound intermittently. If wall studs/battens are found the red LED will come on and an audible will sound at one end of the batten, when the other extremity is located the green LED will come on and a lower pitch audible sound will be heard. Size 150 x 95 mm.