Audemars Piguet Royal Oak Men’s Watch Green Stainless Steel 26240ST. Small Second, Chronograph, Seconds Hand. Audemars Piguet’s Royal Oak delivers beauty by combining the modern colors of white gold and blue. The stainless steel 41 mm case is assembled with a khaki Grande Tapisserie dial, a screw-locked crown, and a water resistance of 164 feet. Powered by the self-winding 4401 calibre, this timepiece has a 70-hour power reserve.