This model, with scratch-resistant sapphire crystal, sports a black ceramic dial, with Arabic numerals and date at 3 o´clock. The unidirectional black ceramic bezel, with immersion scale in OMEGA Liquidmetal ™, is mounted in a box 43.5 mm and noble steel. Alveolar screwed case back and stainless steel bracelet with patented extendable folding clasp. OMEGA Seamaster Planet Ocean 600M Master Chronometer is watertight up to 600 m and has a helium escape valve. It incorporates the OMEGA Master Chronometer 8900 caliber.