Features: Carbon steel material, through fire dipped black surfaces treatments, ensuring its sharper. Rotary burr, processing efficiency than the manual file to improve of times, than with a small handle wheel to improve nearly ten times. Suitable for enthusiasts or craft fan, and give your rotary tool even more functionality with this set of burrs. Works with mostly small rotary tool for carving. Used for grinding, polishing, shaping and burnishing wood, plastics and rubber surfaces. Suitable for woodworking enthusiasts, home renovators who demand versatility in their tool. Specifications: Component:Carbon Steel Color:Gray/Black Size:Approx.50mm/1.96inch 56mm/2.2inch 46mm/1.81inch 42mm/1.65inch Package Includes: 5Pcs Drill Bit note: 1.Please allow 1-2cm errors due to manual measurement, making sure that you not mind before order. 2.Due to the differences between different monitors, the picture may not reflect the actual of the item.