Professional tools: There are 20 different shapes and sizes of rotary cutters, which are very suitable for model making or engraving, etc. You can choose different types of cutting heads according to your work needs, and they will meet your different process requirements. Multi-function tools: Diamond drill bits have 10 different grinding heads, very suitable for engraving, cutting, polishing, chamfering, grooving, boring, drilling, etc. Compatibility: 3mm (1 or 8") rotary tool post is suitable fits most electric rotary tools or grinders, such as Dremel, GOXAWEE, Proxxon, Einhell and similar machines. Quality Material: The milling bits are made of quality high-speed steel with long life, have the advantages of high hardness, good wear resistance and heat resistance. Delivered quantity : 20 pieces Welcometomeet