Oris Men&#39;s 635 7534 4164MB BC3 Automatic Watch Quality Automatic movement; Functions without a battery; Powers automatically with the movement of your arm Scratch-resistant-sapphire crystal Case diameter: 48 mm Stainless-steel case; Black dial; Day-and-date functions Water resistant to 330 feet (100 M): suitable for snorkeling, as well as swimming, but not diving