A. Lange & Söhne

Exceptionally robust and elegantly refined, the Lange 31 is a technical tour de force. When it was first introduced in 2007, the Lange 31 was the world’s first mechanical wristwatch with a power reserve of 31 days and a patented constant-force escapement that continuously delivers uniform torque from the first to the last day of use. Since then, other watches have exceeded this, but the Lange 31’s classic case design and relatively simple dial layout, with its oversized date windows and time and small running seconds display, distinguishes it from its successors. To achieve such power, the hand wound caliber L034.1 featuring 62 jewels contains two mainsprings, one housed on top of the other that are both 1850 millimeters (roughly ten times what is found in watches with conventional power reserves). Rather than winding these mainsprings via the crown, one utilizes a ratcheting winding key that connects to a port in the case back to manually wind the barrels. To ensure the smooth application of this astonishing power is a patented ‘constant force’ escarpment with remontoire spring that ensures the uniform levels of torque are delivered.

46 mm in diameter and cased in pink gold, the present watch is in spectacular condition and is offered with an A. Lange & Söhne presentation box with outer packaging and facsimile guarantee certificate.