Magnetic self-locking mechanism: with a strong magnetic system, the drill bit holder securely locks the drill and allows quick release if necessary. This magnetic technology provides additional comfort and safety to ensure that the bits remain firmly connected during use. Versatile length options: four length options are provided: 2.36, 2.95, 3.94 and 5.91. These varying lengths ensure flexibility and make it easier to tackle a range of projects, from tight spaces to hard to reach areas. High torque and anti slip design: the hex bit holder is designed to handle high torque and provides excellent anti slip performance. This allows efficient power transmission and makes it perfect for difficult jobs where precision and reliability are crucial. Quality construction: this drill expansion bit holder made of high quality carbon steel is designed for high hardness and durability and offers superior performance even in high performance tasks. It resists wear and ensures long lasting reliability. Use scenarios: - Working in tight spaces where reach is limited, use the shorter lengths to access confined areas while maintaining bit control. - Performing high torque drilling tasks in metal or dense wood, where secure bit retention and anti slip are essential. - In professional settings with frequent bit changes, rely on the magnetic self locking mechanism for quick release and reliable retention.