Lange is introducing a new pink gold version of the 31, the first mechanical watch to achieve a power reserve of 31 days. The movement is powered by two stacked mainspring barrels, each with a spring that is slightly more than 6 feet long. A constant-force escapement between the twin mainspring barrels and the going train assures that the balance receives an identical amount of energy every ten seconds, regardless of the state of wind of the springs.
This much power takes up space, making the Lange 31 movement as large as some watches: 37.3 millimeters in diameter and 9.6 millimeters thick. This presented challenges to Lange’s designers. For example, on the dial alone, the designers considered more than 70 versions over 2 years. Tiny details, such as whether the hour markers should be a fraction of a millimeter longer or shorter, were considered. In the end, the designers achieved the classic, timeless Lange look.
The Lange 31 in pink gold retails for $114,000. Look for it to begin arriving at retailers in November.
Complete technical specifications appear below the images.