4-Inch Diamond Turbo Grinding Cup Wheel Coarse Grit for Concrete / Granite Floor for DAMO 1 Piece of 4-Inch Diamond Turbo Grinding Cup Wheel Coarse Grit for Concrete / Granite Floor. with 5/8"-11 Thread arbor. Corase Grit (Grit 30/40). Use dry or wet, maximum speed 11,000RPM.