As sharp as new: The electric sharpener is designed for home and kitchen use, giving you professional results right at home. Works on stainless steel kitchen knives, but not ceramic or serrated. The correct steps for sharpening: insert the dull knife obliquely and touch the outer wall closely as the pictures shown entered, and then pull from outside to inside to sharpen. You will enjoy like-new sharpness after 60 seconds. 2-Stage Design for Sharpening and Polishing: Professional 2-stage sharpening system for crude and fine can perfectly meet your knife sharpening needs. The crude stage can sharpen knives quickly, and the fine stage can polish them more smoothly, delivering a sharp, burr-free edge. 3-in-1 Multifunctional Knife Sharpener: In addition to sharpening kitchen knives, it can also sharpen scissors. Use Tips: We recommend no more than 10 minutes of use at a time, or it will cause the motor to overheat and stop working. The exact time may vary depending on the weather and temperature.