Caution: 1.Do not use the knife sharpener to sharpen serrated blades. 2.To avoid damaging the knife, please sharpen the knife slightly . 3.Do not put the sharpener in the dishwasher or submerge in water. Use: According to the situation of cutting tool choice knife surface,hold knives Keep the sharpener along the bade,blade Angle is moderate,with proper strength can be pulled back and orth,generally 3 to 5 times