Includes 25 Different Sizes with Metric Size Mark: Enables easy and quick picking for various needs, saving time and providing convenience for various projects. Internal Left-Handed Spiral Design: Provides a firm grip and faster tapping, improving efficiency and reducing the effort required for screw extraction. Compatible with Various Aessories: Can be used with a hex drill bit to remove screw, stud, bolt, threaded pipe, pin, and other aessories, offering versatility for different applications. Heat-Treated 42CR Steel Construction: Ensures durability and resi to deformation, providing long-lasting performance and reliability. If you have any questions about the product, please feel free to contact us via email.