This is a double-sided grindstone that can be used with both rough grinding and fine grinding on the front and back surfaces Middle wheels used for scratch erasing, sanding and polishing, and finishing wheels that can be used for finishing are front and back Ideal for small kitchen space, compact size easy to store and easy to use even at home As a rubber with anti-slip sticks, there is no worry about slipping Attention : It is not suitable for ceramic kitchen knives Specification Whetstone size: 18.6 cm x 6.7 cm x 2.8 cm Material: White Alundum (It is a hard ore next to diamond and has excellent durability) How to use 1.Immerse the wheel in water for 5 minutes and place it on a stable surface. Hold the knife so that the blade hits the wheel at an angle of 10 to 20 degrees. 2.Clean the blade and polish it on a sufficiently sharp blade. 3.After polishing, first wipe the grindstone with a membrane, then rinse with water and dry, then wash the surface of the grindstone with a soft brush