http://www.executive-shaving.co.uk/s...ning-stone.php

i can get this fairly cheap from store in my city (8€), but how to use it? am i posed to wet it like norton? and does it have 2 different grits, in picture it looks to have 2 different sides? anyone knows anything bout this? i am going to buy me a 3'' wide norton as soon as i have extra money for it, but that should work better than nothing...