The Samura Combination 240 & 800 Whetstone is suitable for the sharpening of blunt knives. The coarse 240 grit is ideal for reshaping the blade of a blunt knife and removing burrs that have occurred. The 800 grit can be used once the blunt knife is restored to shape for sharpening. The whetstone comes with a rubber holder in which the stone sits firmly during sharpening process. Submerged the whetstone in water for a few minutes before use. Compare prices from: Samura in Kitchen Tools & Accessories