New 50 pcs diamond coated grinder heads in box set. There are many sharp such as sphere, cylinder, bullet, needle, etc..... 1/8" (3.175mm) shank for use with motor tools, drills, high speed die grinders, and flex shafts. Suitable for use in grind the edge of glass, marble or rock. | Come with the PVC box as shown on picture. US-BASED CUSTOMER SERVICE: Available by chat, email, phone, or visit us at our customer service center in La Crosse, WI.