Product Name: Vacuum Brazed Diamond finger bits Milling bits for tile, stone, countertop Specification: Diameter 10MM 20MM 25MM , 50MM workable length, 5/8-11 Or M14 thread, Grit #50/60 Dia 50mm/2": workable length 46mm; 5/8-11 or M14 thread; Grit #80/100; Dia 82mm/ 3-1/4": workable length 49mm; 5/8-11 or M14 thread; Grit #80/100; Quantity: 1pc Application: Enlarge, shape and/or round bevel existing holes in Porcelain, Hard Ceramic, marble and granite Also available to make a hole directly, but not recommend to do this job. Dry or wet used on angle grinder Vacuum Brazed Processing, high diamond concentration provides for a faster cut rate while the high quality of the diamonds provides longer working life Strict production process to ensure the perfect combination of the cutter head and the base. Very useful to reduce the risk of cracking with standard and large format tiles subjected to tension (ex tightened plumbing, led lights etc). Very useful to improve the edge finishing of exposed holes. Very easy to operate. ================THE END================