1x4 Suehiro 20K Gokumyo
The Suehiro 20K Gokumyo is one of the highest grits available in stone form, and allows you to get your edges to mirror finish without the need for strops. Of course, you can continue into the stratosphere with strops after the Suehiro 20K Gokumyo!
Suehiro Stones are all meant to be used with water only, and require a quick 1-2 minute soak before use. To optimize the effects of these stones, keeping the stone free of swarf will give them slightly more aggression while allowing a paste to form will maximize the finish. When utilizing the paste, don't let it get too thick - keep it viscous with a couple drops of water.