Bru Joy Diamond Steel and Ceramic Sharpening System 2 Stage Knife Sharpener Stone 100% SATISFACTION GUARANTEED OR YOUR MONEY BACK! Rubber base ensures the sharpener will not slip when sharpening any knives that you have Two Stage Knife Sharpener, coarse and fine-sharpening design, coarse sharpening is for dull or blunt blades and need to run the knife 2-4 three times.The fine sharpening, smooths knife edge and adds more sharpness PLEASE NOTE - This knife sharpener has been specially designed to only sharpen steel, straight blades for the best performance. Ceramic and serrated knives should NOT be used in the sharpener. Stainless steel surface have wire drawing lines, play a non slip, anti fingerprint, anti oil, and easy to clean.Comparison with plastic material has more excellent performance.