Spyderco Bench Stone GritMade from ultra hard alumina ceramic material, Spyderco's grit bench stone is used like a traditional sharpening stone, but does not require oil or water. Its broad, flat surface is ideal for sharpening woodworking tools and all types of knives and can be easily cleaned with household cleanser, a scouring pad, and water. This 2 inches X 8 inches stone comes in a light blue, dark blue and black polymer case with non skid rubber feet.