We wrapped all the features of the Multi Scanner i 500 into a new sleek form & added our exclusive ACT Auto Correcting Technology. The Multi Scanner I520 One Step wall scanner easily & accurately locates studs joists metal & hot electrical wire. A 4-mode switch provides instant access to all functions. A ultra-bright LCD screen indicates direction edge & centre of studs. This all-purpose scanner is power-packed: Stud Scan finds metal or wood studs & joists up to 19 mm. deep. Deep Scan mode probes further locating studs & joists up to 38 mm. deep behind drywall panelling or plywood. Metal mode detects ferrous metal such as rebar or steel pipe up to 76 mm. deep & non-ferrous metal such as copper pipe up to 38 mm. deep. AC Scan finds & traces live electrical wire. Spot Lite Pointing System & audio alert automatically identify the target. In stud or metal modes Wire Warning Alert detects the presence of unshielded hot electrical wiring. ACT Auto Correcting Technology checks calibration 10 times per second & recalibrates automatically to ensure accuracy.