A. [DOUBLE LOCK] The drill bit extension has a locking device at the interface, which, together with the slight magnetism at the bottom of the hole, ensures that the screwdriver bit or drill bit is securely fastened in place and reduces the likelihood of the screwdriver bit or drill bit wobbling and falling out. The locking device on the magnetic bit holder allows for quick and easy bit changes during use, helping to improve work efficiency. B. [MATERIAL] The bit holder for impact driver is made of metal for enhanced hardness. This drill extension bit holder is suitable for use with impact drivers or drill bit sets. C. [UNIVERSAL USE FOR 1/4 INCH] The quick release bit holder is compatible with most 1/4 inch blades or hex bits, and the impact bit holder itself features a 1/4 inch hex shank. This drill extension is a practical addition to toolboxes. D. [WIDE USE] The impact extension is applicable to electric screwdrivers, pneumatic screwdrivers, hand screwdrivers, t-handle 1/4 inch screwdrivers, corded drills, cordless drills, pneumatic drills, impact drills, or any other device with a 1/4 inch hex shank. The drill bit extender is suitable for maintenance repairs or DIY work in automotive, hardware, home, and other fields. E. [PACKAGE CONTENT] Includes 4 locking bit holders in 4 lengths: 2 inches (60 mm), 4 inches (100 mm), 6 inches (150 mm), and 12 inches (295 mm). Whether for simple projects or complex professional jobs, this magnetic drill bit holder provides options for various situations. F. Colour: Black & Red G. Material: Metal H. Package Contents: 4 * Drill Bit Extension I. Only the above package content is included; other products are not. J. Note: Light reflection and different displays may cause the color of the item in the picture to differ slightly from the actual product. The measurement allowed error is +/- 1-3cm.