The UP/DOWN display reminds the owner to rewind the watch before it stops running. The “AUF” (UP) denotes the fully wound and “AB” (DOWN) the fully unwound state of the mainspring. It is a traditional hallmark of our watches.
The power-reserve indicator
UP/DOWN
The power-reserve indicator was useful especially for precision watches that were relied on for navigational purposes and other scientific applications. It indicates the state of wind and reminds the owner to rewind the watch before it stops running. In the display, the “AUF” (UP) denotes the fully wound and “AB” (DOWN) the fully unwound state of the mainspring. It is a traditional hallmark of A. Lange & Söhne watches.
The 1815 UP/DOWN features a special mechanical implementation of the display. It is no longer a modular addition to an existing movement but instead is integrated directly into the confined space of the movement with a specially designed planetary gearing. The result is a thinner silhouette and more elegant proportions. The compact ensemble is based on a 1940 patent granted to Otto Lange, a grandson of the manufacture’s founder.