This Graef Chefs Choice CC150UK Professional Knife Sharpener for European & Asian/ Japanese Kitchen Knives is very easy to use sharpener. The knife is repeatedly pulled through the slots with the angle fixed by the guide. There are 3 stages of grinding, the rough one is only be used for very blunt knives, the medium is for normal sharpening & fine to remove the burr/polish hone the sharpened blade & is the final stage in sharpening the knife. 100% diamond coated disks in Stages 1 & 2 & a revolutionary polishing disk in stage 3. GRAEF, a family company have stood for high-quality German made ergonomic & user-friendly products for over 50 years. Graefs impeccable range of durable, expertly engineered products are stunning, simple & superb to use.