Commodity Quality Certification : ceThis product may be intended for use by a health care professional use only. The seller may ask you to evidence you are a qualified health care professional entitled to buy and use such products in your country.100% brand new and high qualityThe diameter of burs is 2.35mm. The length of shank is 3.5cmGreat for grinding both metals (i.e. copper, aluminum, etc.) and non-metallic materials (marble, jade, plaster, etc.)HRA processing hardness = up to 80High efficiency grinding - Up to 1000% more efficient than manual files and wheelsReplaces small grinding wheels thereby reducing dust pollutionExtremely durable - Lasts up to 10X longer than than high-speed steel cutting tools, and 200 times longer than wheelsAllows for smooth, precise, and high-quality cuts and finishesSafe, reliable and easy to use Packing List: 1 box including 10 burs as our picture shows