The DMT Duosharp sharpening stone is a large diamond sharpening stone, ideal for sharpening large knives. Each side of the sharpening stone has a different grit size. This sharpening stone comes complete with a plastic base that clamps the sharpening stone in place. Even a simple plastic clamp turns out to be an ingenious aid. Not only can this holder be used with sharpening stones that are 6, 8 or 10 inches long, but the holder itself can also be used in two ways. The usual way is that the foot ensures the sharpening stone doesn't slip while you're sharpening. This allows you to focus purely on the sharpening. There is also a handle at the bottom of the holder that you can use when taking the stone towards the object you're sharpening. One example would be an axe that is clamped in a vice.