Extra Long High-Speed Twist Drill Bits, High Hardness Spiral Drill Bit for Drilling Wood, Plastic, Aluminum and Composite Materials [High-speed Spiral Design]: This twist drill bits adopts a high-speed spiral design, the drilling speed is significantly faster than standard drill bits, and the flutes help reduce friction and heat [Make Drilling More Labor-saving]: The cutting edge of this spiral drill bit is hardened and polished to achieve the purpose of sharpness, the longer size allows you to drill more labor-saving [High Hardness and Durability]: This extra length drill bit is strong hardness, good wear resistance and durability [Scope of Application]: This high speed long drill bits can be quickly installed on most electric drills and drilling machines, which is suitable for drilling wood, plastic, aluminum, etc Color: silver Size: The diameter of the drill bit is 2mm, 3mm, 3.5mm, 4mm, 5mm, and the length is about 150mm Quantity delivered: 5 pieces Warm prompt: 1.As different measuring methods,it will occur 1-3 cm deviation about the items,please ensure that it is okay for you before ordering. 2. Because of different monitors and lamplight, the picture may not reflect the actual color of the item, really thank you for your kind understanding 3. Only the above package contents, excluding other products.