These stones vary from the Japanese in two key areas.
The grit size is just a bit coarser. (There is no International Standard for grit sizes)
The bonding agent is softer than a premium Japanese stone. I don't know that they actually wear faster though, because they produce results much more quickly. I really like the finish produced by the 4000 grit and we use it regularly.
We actually like these stones quite a bit. Nice size, sturdy plastic box that also serves as a stand for the stone. Be very careful to not push the edge into the stone. Draw the knife towards you with the edge facing away. Please call or email with any questions.
Dimensions: 8 x 3 x 1 in.