【The Perfect Gift Idea】: The double-sided whetstone is suitable for almost all types of knives, razors, precision tools, planers, and scissors, except for serrated blades and ceramic knives. It is the perfect gift for family and friends. 【Material】: The double-sided whetstone is made of high-quality red corundum and green silicon carbide, making it very convenient and durable to use. It can be used for a long time and has a long service life. 【Double-sided Whetstone Design】: The double-sided whetstone is convenient and easy to sharpen knives with. It has excellent sharpening performance and is very easy to use. The whetstone uses water for sharpening and cleaning. 【Function】: A 1500-grit side can be used to remove burrs from the blade. The 400-grit side can be used for coarse grinding to shape edges or repair heavily damaged blades. Specifications: Material: Red corundum + green silicon carbide Grit type: 400 grit and 1500 grit Size: Approx. 100 x 35 x 22 mm / 3.94 x 1.38 x 0.87 inches Color: 400 grit: rust, 1500 grit: mint. Weight: approx. 151g Instructions: 1. Soak the stone in water for about 15 minutes before use; saltwater is best. 2. Sharpen the knife in order, starting with coarse and then fine. 3. When sharpening the knife, hold the handle with your right hand, press lightly with the fingers of your left hand against the knife's edge, and move clockwise. 4. The sharpening angle is best between 10 and 20 degrees. 5. Do not scrape off the slurry during sharpening; the knife will be sharper with slurry.