Durable and long lasting construction - Made from high hardness material, this magnetic bit holder set is built for longevity. Its tough, anti slip design withstands high torque for a long service life. Strong magnetism - Equipped with a powerful magnet that effectively self locks the drive shaft, keeping the bit securely in place during use for safe and efficient operation. Practical and versatile design - Features an external hex shank that can be converted to an internal hex. It is compatible with electric screwdrivers, hand screwdrivers, and screwdriver bits, making it suitable for a wide range of applications. Flexible extension set - Includes extension rods in 60 mm, 75 mm, 100 mm, and 150 mm lengths, allowing work in tight and hard to reach spaces. It is perfect for extending rods and reaching difficult areas. Use scenarios - Installing hardware in tight furniture corners with a power drill. - Reaching deep bolts or fasteners in cramped automotive engine bays or under dashboards. - Electrical installations or bicycle maintenance where space is limited and extended reach is required.