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, which can meet your different process needs. Multifunctional tools: Diamond drill bits have 10 different grinding heads, which are very suitable for engraving, cutting, polishing, chamfering, grooving, drilling, drilling, etc. Compatibility: 3mm (1/8") rotating tool holder is suitable for most electric rotary tools or grinders Quality material: The cutters are made of high-quality high-speed steel with a long service life and have the advantages of high hardness, good wear resistance and heat resistance.