The Kitayama whetstone has a grit rating of 8,000 but some stores claim that it is 12,000. The reason for this confusion is that the stone "seems" like a higher grit. We use the actual rating on the stone. The Kitayama whetstone should be soaked in water for about 15 minutes before use. Kitayama stones contain Magnesium salts that will dissolve in water so it is recommended that you do not leave the stone in water for long periods of time.
We recently switched these stones to the baseless version after our customers voted 10 to 1 in favor of the baseless version. The baseless stone allows you to sharpen on both sides.