Customers satisfaction is very important to us! ^_^Features & Specifications:Diamond coated bur set with 2.3mm shanksBits come in different sizes and coarseness to satisfy any technology.Fit most professional electric drills， best for replace nail drill bitsCan be used to various applications including carving， grinding and etching on a variety materials.Bur Shank Diameter: About 0.09 inch/ 2.3mmBurs Length: About 1.77 inch/ 45mmYou Will Receive:30pcs Diamond Burr Bits