Feature: 1. Designed by using principle that the density change of the substance below the surface of the detected object causes the detector frequency to change. 2. Wall metal finder, selected high-quality plastic materials, durable in use and wear-resistant. 3. Suitable for use in interior decoration structures, it can detect the position of metal and wood in the wall. 4. When detecting the location of metal or wood, the detector has an audible and flashing alarm. 5. Hand-held metal detector, small and light, simple and convenient operation, long service life. 6. Just put the detector on tested surface, light up red LED and green LED, and hear "beep" sound. When red LED goes out, the sampling is normal. If the first red LED and the "beep" sound continue to light, the sampling failed. Specification: Condition: 100% Brand New 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.. Package List: 1 x Stud Detector (Battery Not Included)1 x Manual Note: 1.Please allow 0-1 inch error due to manual measurement. Thanks for your understanding.2.Monitors are not calibrated same, item color displayed in photos may be showing slightly different from the real object. Please take the real one as standard.