Quality check..... all good.
If you have any doubts when buying one of these then please just do as i did, email the kind guys at Heinnie and ask them to quality check before despatch.. got mine yesterday and both ceramic and diamond sides were flat and ready to go! used an old blade first to break it in. 1 star dropped due a tiny, tiny gap in bonding between layers but can't see it being a problem. Great stone, excellent service as always.