It is a guide to fix the angle of the knife and a whetstone. Great and useful tool when you sharpen a knife.
Please read before use:
1.Insert the holder onto the knife's spine.
2. Move the position of the holder according to the area you grind.
3. Sharpen the knife while holding it lightly with your fingertips so that the cutting edge does not float from the grinding surface.
4. If one side is ground, the other side is also ground in the same way.
Whetstone Knife Sharpening Angle Guide