Hone and sharpen knife blades with this Messermeister double sided grit sharpening water stone. The 400 grit side will correct slight edge flaws while the 1000 grit side is excellent for both finishing and maintenance. The clog free surfaces of the water stone rest easily in a silicone base for storage. To use the stone, immerse in water for ten minutes or until the stone stops producing bubbles and then push the blade across the desired grit side at a 15-20 degree angle. Backed by a manufacturer's lifetime warranty, this sharpening stone is sure to guarantee satisfaction.