This one tool is all you need to sharpen and bevel your edges. Dial a precise angle from 0 degree t * Five diamond stones included! * Use the gray for serious repairs and removal, black for cutting, the blue to maintain the sharpness * GREY (XX-Coarse)= offers serious metal removal in the shortest time (120 grit); * BLACK (X-Coarse)= offers best cutting action (220 grit);