Precise & Long-Lasting Sharpness: Any serious chef knows quality knives are expensive. Keep yours cutting like new for much, much longer with a Tumbler rolling knife sharpener. With our easy-to-use system, anyone can get factory-sharp knives in minutes. Powered by Diamonds: The sharpening disc is plated with nature's hardest, most-effective sharpening stones: diamonds. The D35 grit size (compare with 800 whetstone grit) effortlessly removes the first layer of your knife’s edge while restoring sharpness. A Finer Edge: A proprietary stainless steel helix disc on the other end of the kitchen knife sharpener removes the burr of your knife’s edge after the base sharpening. The result? A finer edge for more precise cutting that makes all kitchen tasks easier. Simple, But Effective: The Tumbler knife sharpening kit is deceptively simple, but also surprisingly functional. Simply choose your angle and use the magnetic knife holder to secure your blade. Then, roll the sharpening disc back and forth until sharp. Finally, flip Tumbler over and hone the edge using the stainless steel disc. 15 & 20 Degree Angle Sharpening: Easily & quickly sharpen traditional and specialty blades. Powerful magnets keep your knife at exactly 20° or 15°, so you'll always get uniform angles over the entire cutting edge.