Features: 1. The world's simplest stud finder. No batteries required – this stud ball uses magnetism. 2. Quickly and accurately detects screws or nails behind wood frame walls or drywall. Can locate 40 or more steel nails in 5/8 inch thick drywall in less than a minute. 3. No need to mark or take readings on the wall – the magnetic stud ball locates and identifies stud positions directly, ready for use. 4. Easily detects metal through drywall, wood framing, and other thick construction materials. Can detect through up to 3/4 inch ceramic tile and plywood. 5. Can also be used to find small metal objects on floors or retrieve metal items that have fallen into narrow spaces. Notice: 1. Actual color may vary slightly due to different monitor displays and lighting conditions. 2. Please allow 1-3 cm deviation due to manual measurement. Size: 8 x 5 x 5 cm Includes: 1 x Detector