This stone is what I finish most of my kitchen knives at for a slicier edge than the 400 grit stone. It removes metal at a decent rate and seems to be quite hard and will last a long time. If you are sharpening lower quality softer "stainless" steel knives this is probably as high as you want to go. The steel on those generally needs the tooth of this or the 400 grit to perform well or you could end up with a "sharp" knife that glides over things like tomatoes instead of cutting into them.
My stone came in between 3.15mm and 3.3mm end to end, the farthest from flat stone I received when I bought the full set. This is stone (and the 1,000) are thinner than the 120, 220, and 400 grit stones, and all are thinner than what has become standard of 6mm for this format of stone.