Baume & Mercier Men's 8728 Riviera Automatic Chronograph Watch Quality Swiss Automatic movement; Functions without a battery; Powers automatically with the movement of your arm Scratch-resistant-sapphire crystal Case diameter: 40 mm Stainless-steel case; Black dial; Date function; Chronograph functions Water resistant to 330 feet (100 M): suitable for snorkeling, as well as swimming, but not diving