Due to the difference in the material of the knife and the angle of the blade, if the sharpening effect is not good, it is recommended to continue sharpening the sharpening of the mouth, and gradually increase the strength to observe the effect (even more than a dozen times can be sharpened back and forth). Shape processing, sharpness will be achieved after successful shaping, and no further shaping is needed in the future use: 1. Rough grinding, put the blade vertically into the rough grinding mouth (near the handle groove), and pull it back slightly for about 5 times. 2. Fine grinding, put the blade vertically into the fine grinding mouth (middle groove), and gently pull it back about 3 times 3. Fine grinding, put the blade vertically into the fine grinding mouth, and gently pull it back about 3 times Specifications: Name: Multi-function knife sharpener Material: ABS, TPR, stainless steel Size: 18.5 cm * 4 cm × 8 cm Package Included: knife sharpener