Diamond Finger Bits Segment Profile Router Finger Bit for Drilling Granite Stone Marble Concrete CNC MachineFEATURES AND ADVANTAGES: 1. Finger Router Bit designed for stock removal on granite or hard stone grinding away excess stone to prepare for polishing 2. Drilling and shaping of granite, marble, artificial stone, ceramic, etc 3. Good sharpness,blended segments will bring less tremble 4. Faster cutting and longer life; good tools, easy work. 5. Can be installed in angle grinder quickly and firmly and prevent bits from slipping. 6. Recomended speed 4000