Breitling Blackbird Mechanical (Automatic) Black Dial Mens Watch A4435910/B811 (Certified Pre-Owned) Quality Automatic movement; Functions without a battery; Powers automatically with the movement of your arm Scratch-resistant-sapphire crystal Case diameter: 46 mm Stainless-steel case; Black dial; Date function Water resistant to 990 feet (300 M):suitable for scuba diving to a depth of 30 meters for up to 2 hours