Sturdy and DurableThese drill bit extensions are made of high quality carbon steel and chrome vanadium steel, with a strong structure to ensure maximum durability and a sturdy structure for long life. Sturdy and DurableThese drill bit extensions are made of high quality carbon steel and chrome vanadium steel, with a solid structure to ensure maximum durability and a sturdy structure for long service life. Excellent CompatibilityIt has a universal 1/4 inch quick-release hex shank and 1/4 inch hex socket, which is suitable for most drill bit extensions and drill bit extensions for electric and pneumatic screwdrivers. Lightweight and portable The small size allows you to extend the bit to any place to complete any job, and it can be put in many kits . Flexible use The cutting head is magnetic, can be quickly connected or disconnected, and ensures that it stays in place when driving. Three different lengths This kit includes three extension brackets of different lengths. You can use the appropriate extension bracket if necessary. Product Description Specifications: Material: Carbon Steel and Chrome Vanadium Steel< /p> Hex Shank Size: 1/4" Hex Socket Size: 1/4" Length: 6cm/2.36", 10cm/3.93", 15cm/5.9" Quantity: 3 Package includes: 3 x Bit Holder p>