Label given to a watch which has undergone precision tests and received a certificate from an official body (COSC).
The day of the month, displayed in a window on a watch dial at the 3 or 6 o’clock position, or within a subdial at 9 o'clock.
Helium escape valve
Decompression system which allows helium to escape from inside the watch when the watch is worn for professional use in pressure chambers. (Long-term underwater work, crude oil exploration, etc.)
A series of watches whose production run is determined in advance of production and limited to a set number.
Self-locking crown, screwed into the tube of the case, used for highly water resistant divers' watches.
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Stainless steel is certainly the most conventional of watchmaking materials for outer craftsmanship, and offers beauty, strength and affordability. OMEGA uses 316L stainless steel. Known for its corrosion-resistance and high lustre after polishing, this material is often the ideal choice for watches in both daily-use and high-stress situations such as diving and adventure.
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To really appreciate the finer details of a timepiece, OMEGA uses synthetic sapphire crystal with a highly scratch-resistant and anti-reflective treatment. Before the machining and finishing processes take place, the sapphire crystals are produced under the Verneuil process, also called flame fusion. It involves the melting of the raw substance using oxyhydrogen flame and the crystallisation of the melted droplets to form a cylinder. Graded 9 on the Mohs-hardness scale (graded 1-10), the resulting sapphire crystals are virtually scratch-proof and very hard, ensuring an unhindered vision at all times.
Get the latest edition of our official Omega catalogue "The Collection".