BA111OD specializes in mechanical watches. It's crucial to understand the difference between our automatic mechanical watches, which operate based on daily movements. These timepieces continually recharge themselves using an oscillating weight at the back of the watch. On the other hand, our Chapter 4. Tourbillon collection features manual mechanical watches. Unlike the automatic variants, these manual timepieces do not have an oscillating weight and thus, need to be manually wound periodically using the crown to function optimally. This distinction ensures that you choose a watch that aligns perfectly with your lifestyle and preferences.