10pcs Rotary Burrs: In the kit, it includes 10 different 3mm rotary burr pieces: cone burrs, V-shaped burrs, cylinder ect. The shank diameter is 3mm. The cutting diameter is 6 mm. These ten different shapes and sizes of milling cutter will fully meet your needs, make material processing quite easy. Tungsten Material: This drill bit is made of high quality tungsten steel which is strong and has long service life, can resist high temperatures. So the superb quality of the rotary burr will fully improve your efficiency in polishing items. Multi-use: This drill bit kit is not only suitable for metal materials such as cast iron, steel, bearing steel, high carbon steel, chrome-nickel, bronze, brass, but suitable for non-metallic materials like wood, plastic, tiles, marble, jade, bone etc. This makes it ideal for your engraving or finishing work. Applicability: The universal diameter of 3mm is suitable for most rotary tools such as cordless screwdrivers, drill presses and engraving tools. When you're ready to use it, the rotary cutter simply insert the drill bit model you need into the drill. Easy Storage: 10 metal cutter are packed in a box transparent storage. Thanks to the sponge, they will not collide with each other. You can easily take the drill bits out of the box and store them again. Size: as shown Delivered quantity: 10 pieces/set