Zwilling Twin Stone Pro slipsten 3/8 is a perfect tool for sharpening your knives. A whetstone is a tool that is easy to use. You wet the stone slightly before placing the knife against it, then draw the knife's edge back and forth. Distribute the weight evenly over the edge and do not press too hard. This whetstone has two sides, a coarser and a finer one. Start with the coarser side and then polish the sharpness with the 8000 side.