The 6909 is a coarse grit, round edge wheel used for mesial occlusal distal (MOD) gross reduction.
This round edge wheel is also available in the following: 8909 - Fine grit (red stripe) 909 - Medium grit 6909 - Coarse grit (green stripe) 2909 - Coarse grit (gold bur) 5909 - Super-coarse (black stripe)
