Omega Seamaster 300 Master Co-Axial Steel Mens Watch 234.30.41.21.01.001 Box Card. Automatic self-winding movement with Co-Axial escapement. Resistant to magnetic fields greater than 15,000 gauss. Free sprung-balance with silicon balance spring, two barrels mounted in series, automatic winding in both directions to reduce winding time. Bridges and the oscillating weight are decorated with exclusive Geneva waves in arabesque. Calibre 8912. Stainless steel round case 41 mm in diameter. Transparent case back. Unidirectional rotating ceramic bezel with a Liquidmetal diving scale. Domed scratch-resistant sapphire crystal with anti-reflective treatment inside. Sand-blasted black dial with rhodium-plated hands coated with 'vintage' Super-LumiNova. with luminous hands and index hour markers.