1. [Hex key bit set includes 10 most popular metric sizes] 1.5mm, 2mm, 2.5mm, 3mm, 4mm, 5mm, 6mm, 8mm, 10mm, 12mm. Bit Set : 6.35mm / 1/4inch, Length: 100mm (3.94inch). 2. [High quality] Heat treated, durability, high toughness, not easy to carry. Make sure you choose the correct bit and control the correct speed of the drill. This operation greatly prolongs the life of the hex bits. 3. [Professional hex adapter bit set are made of high quality material, very well made and sturdy as nails] -Hardness can reach HRC60 degrees. Hex key set suitable for electric drills with speed regulating device, electric screwdrivers, hand screwdrivers. Do not use drill bits in pneumatic tools, air drills or electric drills without speed regulation. Long bit life is achieved due to its durable construction and superior technology. 4. [Nickel-plated surface treatment, super Anti-rust] High quality, long-lasting and durable. The Hex Bit Set is clearly marked that you can find the size you need quickly. Easy to carry and use. 5. [Magnetic bits] -The hex screwdriver set is a bit magnetic, which helps keep nuts and bolts stuck. It can improve the efficiency of your work. Thumb! Longer than those on the market, more practical and convenient. Type: Magnetic Screwdriver Item Name: Hex Screwdriver Bits colour:Black Material:Metal Package Contents: 10 x Screwdriver Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.