The FletéçaKnife sharpener, safely sharpens any kitchen knife hands-free Sharpens hardened steel knives and chef's knives (e.g., Global, Sabatier) Also sharpens serrated knives (e.g., bread knives, hunting knives) Needs only gentle pressure. Lower risk, hands-free use. PowerGrip suction cup securely attaches to any Is designed to be safer 1) Patented PowerGrip suction cup - for your safety The sharpener has a unique safety feature: its PowerGrip suction base, which attaches securely to any worktop, without any tools required. In fact, it can be attached to any smooth surface, anywhere. You can even use it on a vertical surface, like a tiled wall! Once attached, you can safely sharpen any knife using just one hand - keeping your free hand out of harm's way! 2) Polymer Guard - Keeps Your Knives Safe Once the knife has passed its full length through the sharpening nozzle, the blade may touch the sharpener as it exits. The sharpener features a polymer blade guide, which is durable and more flexible than metal. This protects the metal edge and also ensures the protection of your knives. 3) Light pressure is all it takes. Less risk of accidents! When first used on a completely dull knife, it restores a perfect angle and removes excess metal quickly. After this stage, light pressure is all that is needed for best results, and only a microscopic amount of metal is removed. No technique required. Brilliant results accessible to all! The optimal angle for sharpening a good quality steel knife is 20 degrees. It is factory-set at 20 degrees, for perfect results every time. Achieving a consistent angle with a whetstone requires some experience, but thanks to this, it is not necessary, and professional results are within everyone's reach. Once fixed to a work surface, you can sharpen your knives effortlessly and safely, using only one hand. Simply gently pass the blade through the tungsten carbide sharpening tip, 3 or 4 times, to restore an exceptional edge.