1,technology support for using bits by cnc engraving machine 2,it is good for engraving 3D finishing Specification: Model Shk(mm)Ced(mm)degreeOvl ... .2. Art glass, emerald, glass decoration processing.3. Cutting, clearing bottom, drilling, 2D, 3D carvingMaterial applied for:Glass, ceramics, silicon slice ... , malmstone and so on... Hard and fragile materials procession. Diamond engraving bit