Black Bay 58

METAS Master Chronometer certification is comprehensive and covers the main functional characteristics of a watch includingprecision, resistance to magnetic fields, waterproofness and power reserve. Its standards are incredibly high, starting withprecision. Two prerequisites are necessary for obtaining the certification: Swiss manufacturing must conform to Swiss Made criteria,and the movement must be certified by the Official Swiss Chronometer Testing Institute (COSC). Certification by the Swiss OfficialChronometer Testing Institute (COSC) Precision at two temperatures, in six different positions and at two different levels of powerreserve: 100% and 33%. Waterproof to 200 m (660 ft) in accordance with ISO standard Smooth functioning when exposed to a magneticfield of 15,000 gauss and precision following exposure 65-hour power reserve