Omega Speedmaster Date Mens Watch 3513.20. Stainless steel case and bracelet with Olympic rings engraved on back and lacquered white dial. Swiss self-winding automatic movement with rhodium-plated finish. 44 hour power reserve. Scratch-resistant sapphire crystal with anti-reflective treatment inside. Water resistant down to: 30 meters / 100 feet. Approximatley 39mm in diameter.