The A. Lange & Sohne Grand Lange 1 41mm Moon Phase Lumen watch. Model reference: 139.035. This model was introduced at the SIHH exhibition in 2016, and was produced in a limited edition of 200 examples. Scratch resistant black-tinted, semi-transparent sapphire crystal blocks most visible light but not the UV spectra that charges the luminous pigments on the background of the date aperture, allowing them to glow in the dark. There is a rectangular quick date-correction button on the case edge at the 10 o’clock position, and another indented corrector at 8 o’clock. It has a screw down winding crown and an exhibition sapphire display case back secured with 6 screws. The 41mm diameter solid three-body case, curved lugs, and stepped bezel, are polished. The dial is created from semi-transparent coated black crystal; the combination time dial and glass lunar disc has a treated surface that’s laser-cut to create 1164 stars, while the moon sparkles due to the luminous compound behind the disc. It has white gold sword hands with luminous inserts, a white luminous minute scale, and applied faceted white gold diamond-shaped hour markers and Roman numerals at 3, 6, 9, and 12 o’clock. There is a gold-rimmed double big date aperture window at the 1 o’clock position, a 72-hour up/down power reserve arc between 2 and 4 o’clock with a white gold sword indicator with a luminous insert, and a large subsidiary running small seconds dial is at 5 o’clock with luminous white Arabic numerals and a luminous white indicator hand. It’s water resistant to 30 meters/100 feet, and the 9.5mm thick case, dial, and movement are all signed. This piece has a mechanical hand-wound ALS caliber L095.4 movement. It’s made of Glashütte 3/4 plate in untreated German silver with a cotes-de-Geneve striped pattern. It has a classic screw balance with free-sprung balance spring crafted in-house, and it’s constructed with 45 jewels, 446 components with beveled edges, and the balance-cock and intermediate wheel bridges are hand engraved, making every watch slightly different. It includes a straight-line lever escapement, a monometallic balance that’s adjusted to 5 positions, and a self-compensating flat balance spring also made in house. There is a swan-neck micrometer regulator, a shock absorber device, and the mechanism oscillates at a frequency of 21,600 vph (3 Hz). Once properly set, the moon-phase display only needs to be corrected by one day every 122.6 years. Included is a hand-stitched, black crocodile strap with an A. Lange & Sohne, platinum ardillon buckle. Case, dial and movement signed A. Lange & Sohne. The watch comes in original packaging, with a set of documents.