Baume & Mercier Men's 8797 Riviera Chronograph Strap Watch Quality Swiss Automatic movement; Functions without a battery; Powers automatically with the movement of your arm Scratch-resistant-sapphire crystal; Band width between lugs 11.5 mm; Band width at the widest point: 24.5 mm Case diameter: 43 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