Tresor Co‑Axial Master Chronometer 40 mm

From the retailer listing

Characterised by its thin and elegant case, the Trésor line was first launched by OMEGA in 1949 and housed the legendary 30mm calibre. More than half a century later, it continues to impress with one of today’s most advanced mechanical movements. This model has a 40 mm stainless steel case with a diamond-paved bezel and is presented on a blue leather strap. The domed blue patterned dial includes a date window at 6 o'clock as well as hands and indexes in 18K white gold. Inside, this De Ville Trésor is powered by the OMEGA Master Co-Axial Calibre 8910 and is certified as a Master Chronometer at the industry’s highest standard of precision, chronometric performance and magnetic resistance.