It stays well clear of the typical men’s watch diameter of 40 or 42 mm, while not shrinking down to the more compact 36 mm, which is starting to become more commonplace. Longines says the watch ...

The Ultra-Chron story began in 1966 when Longines introduced the world's first mass-produced high-frequency precision watch. This groundbreaking timepiece, known as the Ultra-Chron ref.