This combination water stone is double sided and comes with a rubber base to secure the stone while sharpening. Grit #300 is used to repair nicks, damaged edge blades or dull knives. Grit #1000 is used for basic sharpening. Before sharpening, pre-soak the whetstone for 10-20 minutes and keep the stone slightly wet during the sharpening process. Next to taking your knives to a professional sharpener, this is the choice sharpening method of many chefs. The stone measures 7.25 X 2.5 X 1-inch. Made in Japan.