Description: Stud Finder Sensor: The stud sensor uses electronic signals to locate the edges of metal studs or wood joists through drywall and plywood up to 3/4".With Water resistant but not waterproof, Shock Resistant body for a long life. Edge Detection LED: Once the edge of a stud has been detected,the stud sensor displays a red LED and sound.A pencil notch allows you to easily note the stud edge on the wall (Please wear safety goggles to protect your eyes). Battery: Open door on back of unit and connect a 9volt F622 battery (Not included) to clip.Put battery back into case and close back battery door. Stud Center: 1/8"3mm) for wood; 1/4"(6mm) for metal.Shock Resistance is Up to 3 feet(I m)dropped onto concrete. Depth Range Accuracy Scanning and Up to 3/4" (19 mm) at 35-55% relative humidity. Note:Please remember that studs or joists are normally spaced 16 inches or 24 inches apart and are 1-1/2 inches in width. Specification: Material: ABS Plastic Product Size: Approx. 13.6cmx2.3cmx5.0cm/5.35inchx0.91inchx1.97inch Packing Size: Approx. 14.4cmx2.6cmx5.5cm/5.67inchx1.02inchx2.17inch Operating Temperature: +20F to +120F (-7C to +49C) Storage Temperature: -20F to +150F (-29C to + 66C) Package Includes: 1 Piece Stud Finder Sensor Note: 1. Please allow slightly error due to manual measurement. 2. Due to the difference between different monitors, the picture may not reflect the actual color of the item. 3. Wish you a wonderful online shopping!