Perpetual calendar The calendar display of a mechanical watch is called "perpetual" if it automatically updates the date, the day of the week, the month, and the moon phase displays. It not only takes into account the different durations of the months in the course of a year but also "knows" which years are leap years. The complex mechanism is controlled by so-called cams.

ZERO RESET Patented mechanism that simplifies the synchronisation of the watch with a time signal. When the crown is pulled, it automatically causes the seconds hand to jump to the 12 o'clock (zero) position.

Moon-phase display A disc that rotates under the dial and is visible through an aperture. It shows the moon phases from full to new, generally as seen from the Northern Hemisphere.

Outsize date display Depending on the size of the watch, this useful function makes it possible to display the date up to five times larger than in a conventional watch of similar dimensions. It is based on the patented two-disc mechanism.

Perpetual calendar The calendar display of a mechanical watch is called "perpetual" if it automatically updates the date, the day of the week, the month, and the moon phase displays. It not only takes into account the different durations of the months in the course of a year but also "knows" which years are leap years. The complex mechanism is controlled by so-called cams.

Synodic lunation A synodic lunation of 29 days, 12 hours, 44 minutes, and 3 seconds is the average time between two full moons (or two new moons).

Crocodile leather A popular term for alligator skin. Lange uses only crocodile leather from breeding farms that comply with legislation governing species-compatible animal husbandry.

Luminous hands and markers Hands and markers that emit light in the dark for several hours after having been exposed to sunlight. In Lange watches, they are coated with "Superluminova", a phosphorescent substance.

Sapphire crystal Glass made of artificially produced sapphire. It is very hard (9 on the Mohs scale) and scratch-resistant. It ranks just below the diamond in these two respects.

Wave bracelet Precious, hand-finished detachable bracelet made of 18-carat gold or platinum for the LANGEMATIK-PERPETUAL.

With this showpiece of ingenious technology, Lange demonstrates that the usefulness of mechanical wristwatches can indeed evolve further even after 100 years. All indications of its | perpetual calendar - the date, the day of the week, the month, the 4-year/leap-year display, and the | moon phase - can be advanced separately with individual push-pieces or collectively with one main push-piece. In concert with the | perpetual calendar, the easily legible date display is upgraded to a perpetual | outsize date. It does not have to be corrected until 28 February 2100, the next date on which our calendar year must be re-synchronised with the | solar year. And on that date, all it takes is a simple press of a push-piece recessed in the case. The | moon-phase display is also a model of supreme precision. Once correctly set, it will move continuously for 122.6 years before the aggregate error relative to the | synodic lunar orbit amounts to one full day. The small-seconds hand seems to float above the gold moon disc. It is linked with the extremely useful, patented | ZERO RESET mechanism. This watch asserts its claim to eternity with inconspicuous details as well. The dial is made of solid silver, the appliques of solid gold. Despite the many indications, the dial expresses great composure. The gold hands that display the hours and minutes are coated with a | luminous compound. The LANGEMATIK-PERPETUAL is available in 18-carat pink gold or platinum. It comes with a hand-stitched | crocodile strap or, optionally, with the | wave bracelet, a paragon of the art of goldsmithing. The unprecedented Lange L922.1 SAX-0-MAT movement can be admired through the | sapphire-crystal caseback.