TS78B Multi Functional Electronic Wall Metal Stud Finder Detector AC Wire Scanner Instrument Condition: Item Type: Stud Detector Material: Plastic Power Supply: 1 x 9V 6F22 Battery (Battery Not Included) Weight: Approx. 95g / 3.4oz Detection Depth: Approx. 19mm / 0.7in Positioning Accuracy: Approx. 3mm / 0.1in Product Size: Approx. 145x62x25mm / 5.7x2.4x1.0in Operation Method: After sampling is normal, do not release the power button. Move along the measured surface. When STUD is detected, the red LEDs light up in sequence; when all the red LEDs light up and make a sound "beep", marking the first position, and then release the power button. Place the detector on the surface to be measured, resample and move from the opposite side to the position of the first marks. When STUD is detected, the red LEDs light up in sequence; when all the red LEDs light up and the sound "beep" sounds, marking the second position, and then release the power button. If the alarm repeats, repeat the test for a period of time. STUD may exist between the first and second marking positions. Move the detector away from the test object, move the knob until it emits sound and shines, and move back a little to stop the sound and gloss. The detector will not emit light or sound without metal or studs. Test for a while to get accurate results.