If you are going to buy a mechanical watch, you'll probably care how long the power reserve in the watch can last since you have to wind your watch once the power reserve in the watch is run out. Usually standard mechanical wrist watch has a power reserve of about 40 hours, which means you have to wind your watch in less than every two days. Is it a little bit trouble?
A. Lange & Sohne provides a super endurable mechanical watch for those mechanical watch lovers. With the innovative design that employs two large mainspring barrels, the power reserve in the Lange 31 timepiece is far more endurable, it can last up to full 31 days! This is so far the longest power reserve in record.

The ultra exclusive watch took years to research and perfect. It was not commercially available until over a year after it was even announced, due to intense testing for reliability. The manually wound, A. Lange & Sohne manufacture-made movement requires a special key to be wound (with a socket on the rear of the watch). The Lange 31 movement has the time, out-size date, subsidiary seconds dial, as well as a large power reserve indicator. The movement relies on a
specialized constant force escapment to stay accurate throughout the unwinding of the stacked mainspings.
The Lange 31 watch is available in platinum and in 18k rose gold. Its price is estimated to over $300,000. If you like A. Lange & Sohne watch, you can buy a
replica watch at quite affordable price. The watch's same look and design as the original one will make you love it at your first glance.