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.