The ceramic sharpener was invented by Louis Graves. We have always disagreed with Louis about the proper angle for the rods, but in every other way, he really knew what he was doing. The 90+% Alumina Ceramic rods will sharpen your knives for years and years. In fact, the only way to wear out these rods is to break them by dropping on a hard surface. Just keep the knife straight up and down and as if scraping a decal off of the surface of the rod, draw the knife down, one side of the "V" and then the other. This will quickly give you a razor like edge. I use this device daily and think there is no better way for most people to sharpen their knives.
You can buy all of the sharpening gadgets in the world, including some very expensive machines, and they will not add up to the value of this great device. Walnut base measures 10-1/4" long with two sharpening rods.