The Chef?sChoice┬« Pronto? Manual Diamond Hone┬« Knife Sharpener 464 (model: 464 and 4640100) is easy to use, quiet and extremely fast. This knife sharpener is the fastest manual sharpener on the market and puts an extremely sharp edge and long-lasting edge with lots of bite on straight edge and serrated knives. Using the Chef?sChoice perfected Criss-Cross? technology, this two-stage sharpener features 100% diamond abrasives and precise bevel angle control for a 20 degree edge. The Chef?sChoice┬« Pronto? applies an extremely sharp double bevel edge with microscopic ?teeth? along the cutting edge. These tiny teeth provide the ?bite? on the edge and work to engage and stabilize the food for effortless cutting.