Nice thick stone.
Hard and fine Ozuku stone LV5 fineness and LV5 hardness. These are fast, fine and exactly what you would expect from Ozuku, just less expensive than a premium sized stone from this mine. These Ozuku koppa will need a little work to polish the face, and possibly stabilize small cracks, they are priced as such.
Being koppa there are roughly cut and do not have a polished face or lacquered sides, measurements are from the widest dimensions.
This stone is great for razors but less suitable for most knives, there can be applications for a stone of this hardness and fineness with ura of single bevel knives and tools that benefit from a fine finish but the stone will be scratchy on the wide face of a steel with large carbides.