Power-reserve indicator

NOMOS Tangente Power-reserve indicator

The power-reserve indicator displays the state of wind of the mainspring. It reminds the owner that the movement must be rewound again before it stops. The power-reserve indicator is a very useful horological complication, as it lets the wearer know whether a watch is wound before putting it on. This is applies particulary to automatics, where the state of the wind is unknown, or to those manually wound watches that may have a power-reserve indicator of up to 8 or 10 days or so. Often called "UP-and-DOWN display" by Lange.

UP and DOWN display

Dornblüth with UP and DOWN display

The UP and DOWN display indicates the state of wind of the mainspring. It reminds the owner that the movement must be rewound again before it stops. It is also called "power-reserve indicator".