The Naniwa Super Stones are made with a resin bond, which allows for a higher level of abrasive particles compared with less expensive methods of stone bonding. The higher abrasive levels contribute to the speed of sharpening. This 1k stone is very popular grit because it is really starts to refine the edge. It is great after using the 220 or the 400. If the edge is not dull or does not need a new bevel set, you donít need to start any coarser than this. These are splash-and-go stones, so no need for soaking prior to use. They measure 210mm x 70mm x 20mm. We are happy to be the only US distributor of Naniwa Super Stones that come in the larger 20mm thickness without bases.