Extra-Fine Ceramic Stones are used for light honing of straight edge blades. Since very little metal is removed during use, they are excellent for finishing the edge after coarse sharpening or maintaining already sharp edges. Use these replacements stones for the Adjustable Angle Pull-Thru Knife Sharpener.Sharpens a wide variety of knivesTwo stage sharpening for standard knives (coarse & fine)Serrated blade sharpener (fixed angle)Will quickly sharpen very dull or damaged bladesCan be used to maintain the edge on knives that are already sharpWARNING: This product may contain chemicals known to the State of California to cause cancer, birth defects, or other reproductive harm. For more information go to www.p65warnings.ca.gov