A great low grit stone is a must in sharpening quality kitchen knives. This low grit range is perfect for not only re-setting edges before using medium grit stones, but also for removing large chips and fixing broken tips. This stone uses diamond abrasive, making it slightly higher price point and difficult to re-surface the top layer (we don't recommend using ATOMA or other diamond lapping plates on this stone, instead use a Naniwa Traditional #1000 or the nagura to flatten/resurface fresh abrasives) However, it rewards the users in excellent sharpening speed, and it retains its flatness much longer than other types of stones. 

Recommended usage: This is a splash-and-go stone, meaning no soaking prior to usage necessary. It excels at creating a toothy edge very fast, and requires a bit more attention from the sharpener when deburring. If you are sharpening a lot of edges (folder & fixed blades included) often, and can't be bothered with cleaning up slurry and flattening, this is a great stone. We do not recommend this stone for polishing laminated wide bevels, for it provides no contrast between hard and soft steels. It can be useful for re-setting over-sharpened ura of a single bevel blade. 

Brand: Naniwa ナニワ研磨工業 
Product Type: Whetstone
Grit: #400
Size: 210 x 75 x 16mm (1mm of Diamond Abrasive)
Comes with a Nagura