Quantity: One piece Color: Black Material: PC/ABS Product size: 140*70*29mm Packing size: 226*145*35mm Bare metal weight: 80.8g Package gross weight: about 150.5g Quickly identify stud and joist edges; ideal for TV/paint/cabinet installations, towel racks, garage shelves, etc. One-touch design makes things simple; no learning mode required; rugged, ergonomic housing withstands daily field use. 4-level LEDs light up in sequence as you approach the stud; smart sensor will beep if you have calibrated or found something. Inspections up to 3/4" deep through drywall (1/4 to 3/4" thick), wallpaper, and fabrics; It is necessary to calibrate the wall before inspection (put it on areas without calibration bolts)Good quality product