Professional quality sharpening stones, Quick easy and only requires water,3 assorted surfaces:COARSE: Excellent for sharpening plane irons chisels garden shears lawnmower blades etcMEDIUM : Used to refine cutting edges of blades shears etc can be used to hone edgesFINE : Used to Polish fibe cutting edges for precise sharpnessSizes: 2" x 6"（50mm x 150mm）