Specifications: 0.31inch small hole diamond grinder head on hardened base. Guaranteed not to peel, reduces shaft binding. Universal for all grinders such as suitable for certain brands. Stained glass grinder head bit is metal for superior strength and long life. A big grinding surface: abrasive height is 3cm. Item Name: Grinding Head Bit Material: Metal Feature: Portable, Durable, Accessories MCB01 Size: 35mm x 25mm/1.38" x 0.98" (Approx.) MGB34 Size: 39mm x 19mm/1.54" x 0.75" (Approx.) MGB14 Size: 35mm x 6.3mm/1.38" x 0.25" (Approx.) MCB18 Size: 35mm x 3mm/1.38" x 0.12" (Approx.) Notes: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement. Package Includes: 1 x Grinding Head Bit