The Fissman 's corundum sharpening stone helps to restore a super sharp cutting edge to blunt knife Blades that have dulled with use. The comfortable and safe design of the sharpener does not require a lot of time or effort to maintain the Blades in perfect condition. The silicone base prevents slipping of the stone during operation. Soak the stone in water for 5 - 10 minute until air bubbles disappear, then place it on a flat steady platform. , , While holding the knife at an angle of 10-30 degrees move the blade along the surface of the stone with a gentle pressure. Do this until a fine edge appears on the opposite side the blade. Not suitable for serrated knives.