The entire Planet Ocean Deep Black line is a large 45.5 mm in diameter. They are all built from a single block of ceramic, and feature helium escape valves at 10 o’clock. Inside, you’ll find the excellent OMEGA Master Chronometer caliber 8906. As you may remember, all Master Chronometer movements pass eight tests set forth by METAS, and are resistant to an incredible 15,000 gauss. So you have an anti-magnetic movement with COSC accuracy, and a four year warranty.