A. Lange & Sohne Lange 31

The LANGE 31 is the world’s first mechanical wristwatch with a power reserve of 31 days and a patented constant-force escapement. The white-gold model has a grey dial made of solid silver. Limited to 100 pieces, this model is available exclusively in Lange boutiques.
Case dimension
Case diameter: 45.9 mm
Case thickness: 15.9 mm
Winding mechanism
Manually wound movement
Power reserve
744 hours
Complications
Outsize date, Constant-force escapement, Power-reserve indicator
Reference
130.039F / LSLS1303AC
Limited
100 pieces
Dial colour
Grey
Case material
18-carat white gold
Case back: sapphire glass
Case dimension
Case diameter: 45.9 mm
Case thickness: 15.9 mm
Water resistance
3 bar
Movement designation
L034.1
Number of movement parts
406
Winding mechanism
Manually wound movement
Power reserve
744 hours
Balance frequency
21,600 semi-oscillations per hour (3.0 Hz)
Complications
Outsize date, Constant-force escapement, Power-reserve indicator
Leather Strap
Brown, Alligator leather
Our alligator straps fully comply with the CITES regulations: Species – alligator mississippiensis. Extraction method – farmed. CITES Appendix – Appendix II
Deployant buckle
18-carat white gold