This is a water stone that requires soaking (5 minutes) before use. Stone. This means that the bond between abrasive grits is weaker, allowing dull grits to break in use, exposing fresh, sharp grits. This causes the stone to cut faster (it stays sharp), but it also means the surface of the stone wears down much faster, causing the surface to become uneven. The water stone must be regularly rubbed with a diamond plate to maintain its flatness. This is perhaps less important when sharpening knives, but is critical when sharpening woodworking blades. The aluminum oxide leveling stone included in this set just doesn't cut it when it comes to precision. The stone measures 6 cm (2.362 in) by 18 cm (7.086 in). The length is good, but the width is slightly less than a 2-3/8 inch plane. It turns out that this isn't a problem in use, as long as you move the blade left and right to compensate for the slight protrusion as you slide the blade across the stone. For narrow blades, like a log plane (or chisel), the width of the stone will do. The base is fairly light but holds the stone firmly and collects any drips from the saturated stone. With its non-slip feet I think it works quite well. The 1000 grit side cuts fast enough that I can remove any small nicks and restore the edge. The 6000 grit polishes the blade well and I use a little extra ridge on the back of the blade to create a micro bevel. The 6000 grit side is also great for deburring. I complement this with a clean which I think improves the edge even more but right after 6000 grit you have an extremely sharp edge. In general, I think this is very healthy water. Stone.