The Audemars Piguet Royal Oak Perpetual Calendar reference 26574ST.OO.1220ST.01 was introduced in 2015. At 41mm, its case is slightly larger than its predecessors. Accordingly, the self-winding caliber 5134 is slightly larger as well – plus a week number indicator has been added. In this configuration, case and bracelet are stainless steel; the dial is silver and features the famous ‘Grande Tapisserie’ pattern.
