uxcell 30 Pcs 3mm Dia Tapered Grinding Head Diamond Coated Point Product Name : Grinding Head;Material : Metal, Diamond Head Diameter : 3mm/0.12";Head Length : 7mm/0.28" Shank Diameter : 3mm/0.12";Total Length : 45mm/1.77" Color : Dark Gray;Weight : 101g Package Content : 30 x Grinding Head