Sharpening Stone Grit: #400/1000 #3000/8000 #1000/4000 #1000/6000 #1000/6000 #3000/8000. 【Durable Material 】-This knife sharpening stone is made of white corundum (alumina) material, which features high temperature, high hardness, wear resistance, high tensile strength, strong and durable, and is not easy to break.
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