The fusée-and-chain transmission ensures that the going train is always driven with the same amount of torque, regardless of the state of wind of the spring barrel. This improves the rate accuracy of the watch. This intricate mechanism was used only in the most complicated pocket watches developed by "A. Lange & Söhne". The latest-generation fusée-and-chain transmission developed by Lange consists of more than 600 individual parts and proves that it can also be integrated in the case of a wristwatch - in the TOURBILLON "Pour le Mérite" and in the TOURBOGRAPH "Pour le Mérite".