The I.O. Shen Manual Knife Sharpener is a much more durable knife sharpener than other manual sharpeners and is suitable for use with straight-edge kitchen knives. It is simple to use and can sharpen the knife once. Rotate the sharpening wheel once or twice to make the sharpening result much better. The I.O. Shen Manual Knife Sharpener has a 360-degree sharpening wheel, which is different from most manual knife sharpeners that only have a single V-shaped spot.