With the release of the new Audemars Piguet Royal Oak ref. 15500 with a 41 mm case, the 41 mm Royal Oak reference 15400 is now officially discontinued. While many felt that the reference 15400 was not perfect, to us it was a very well balanced Royal Oak in terms of overall proportions and design. When the Royal Oak reference 15400 first came out in 2012, collectors of the brand were critical about the fact that the AP calibre 3120 seemed relatively too small for a 41 mm case size —as it was originally launched for the 39 mm reference 15300—, and that due to that, the date aperture was positioned too far to the left needing a small hash marker to its right.