Audemars Piguet presented a concept watch as well just now. This concept Royal Oak RD#2 is housed in Platinum, the case is sized at 41mm with a height of 6.3mm only which makes the watch the thinnest automatic winding Perpetual Calendar. The calibre 5133 is only 2.89mm high. Powerreserve of 40 hours. Not sure if this watch will make it into regular production.