Omega Seamaster, Diver 300M, CO-Axial Master Chronometer, 42mm, Anti-magnetic, Automatic Watch, Chronometer, Date, Helium Escape Valve, Master Chronometer Certified, Screw-in Crown, Transparent Case Back, Unidirectional Rotating Bezel, Lugs: 20mm, Bracelet: Steel, Case: Steel, Case Diameter: 42mm, Dial Color: Blue, Crystal: Domed scratch-resistant Sapphire Crystal with Anti-reflective Treatment on Both Sides, Water Resistance: 30 bar (300 metres / 1000 feet) (210.30.42.20.03)