Audemars Piguet Royal Oak Men’s Watch Silver Stainless Steel 15510ST. Audemars Piguet’s 50th Anniversary adds a modern twist to the classic Royal Oak. The stainless steel 41 mm case is assembled with 32 jewels, a water resistance of 165 feet, and a silver’Grande Tapisserie’ dial. This timepiece is powered by the self-winding 4302 calibre with a 70-hour power reserve.