Lansky delivers the most versatile 3 Stone Sharpener available, harnessing the best of 3 worlds: Diamond, Alumina-Oxide and Ceramic. The full Diamond surface is the fastest way to reset an edge. The long lasting Alumina-Oxide and Ceramic surfaces are used for sharpening and finishing. The result is a stand alone sharpening center that will do it all, with better versatility than other similar products and last longer doing it. Each sharpening surface is about 6 inches long and 2 inches wide.