Sharpen like a pro! With the two-sided whetstone, you can sharpen your knives in a traditional Japanese way. Coarseness 1000 is used to restore the blades' original form. Coarseness 3000 is used to polish the edges of the blade. The two-sided stone stays in place and won’t scratch any surfaces due to its rubber base. The knife angle guides sharpen at 20° which is the norm for European knives. The package also includes two knife angle guides to keep the blade even and at the perfect angle and a polisher for the whetstone.