Audemars Piguet Royal Oak Offshore Men’s Watch 42MM Stainless Steel Black Leather 26170ST. 50 m (5 ATM). Housed on a hand stitched “hornback” leather strap, the Black Dial Chronograph from Audemars Piguet features an iconic Grande Tapisserie pattern paired with volcano red Arabic numbers. The stainless steel 42 mm case is assembled with a fixed, stainless steel bezel and a water resistance of 165 feet. Powered by the 3126 / 3840 calibre, the Volcano Royal Oak features a 50-hour power reserve.