General description This Portable Precise Thread Size Checker Keychain is an indispensable tool for accurately measuring both Metric (8 - 25 mm) and SAE (5/16 - 1 inch) sizes. Ideal for professionals and DIY enthusiasts, it ensures you have the right size at your fingertips for any task. Designed for portability, this compact thread size checker easily attaches to your keychain, making it a perfect companion for on-the-go measurements and quick size confirmations. Technical specifications Metric size range: 8 - 25 mm SAE size range: 5/16 - 1 inch Material: Zinc Alloy Measurement allowed error: +/- 1-3 cm Usage This Bolt Size Finder Keychain eliminates guesswork and avoids the inconvenience of testing multiple sockets. It provides fast and accurate measurements, enhancing productivity and reducing downtime. Its user-friendly design features clear markings that facilitate quick learning and efficient use, ensuring accurate results every time. Other information Colour: Silver Package