Very weird stone, it is razor finisher from a mine Kouzaki. Kouzaki is very Famous for they Super hard Aotos.
And it actually feel somehow how hard Aoto, But of coarse more finer :) That stone needs a lot of smoothening before use.
But it is really amazing finisher if you want to try something new and different ! :)
I have tested this stones for some time now. They feel very different then any other Japanese razor finishers.
Very hard but still super fast ! Produces very fine edge. Need to be used with nagura.
This one is Extra Big and Extra clean, very smooth stone
Size: 165mm 100mm 42mm