A. Lange & Söhne caliber L034.1

Hand-wound movement with a power reserve of 31 days. The energy is stored in the large twin mainspring barrel, which actually consists of two stacked barrels with an inside diameter of 25 millimetres. Each of them accommodates a 1850-millimetre long spring, which is up to ten times as long as in conventional mechanical wristwatches. When fully tensioned, the barrels store more than 3 joules of energy.v