Never before has it been such a pleasure to sharpen your knife! Not only is it fun to handle the new Flipstones, but these diamond and ceramic sharpening stones will create a perfect edge on any knife. The diamond stone is coated with titanium aluminum nitride, while the ceramic one is made of synthetic sapphires. Both materials are extremely hard, grading 10 and 8 on the Mohs hardness scale, respectively. They also provide a smooth and flat surface that will facilitate the sharpening process, even with the hardest special powder steels. Both stones are interlaid with 3M tape and cannot be separated. They are used dry, although a little water and soap can be used to clean the surface. If they feel a bit rough at first, they will gradually smooth out and improve with age. Instructions: Hold the flipstone in your left hand. Push the closure of the top section of the handle forward and press the visible round button. A steel spring will automatically deploy the sharpening stone and lock it in place. To store it, press the round button and push the stone with your hand. Fold the closure to prevent accidental deployment.