Swiss Jaeger-LeCoultre clock, model ATMOS 528-8, serial number 121517, dating from 1952, featuring 15 jewels. The clock has been recently serviced, some parts have been re-nickeled, and it is in excellent working order.Dark blue dial. Here we have one of the most extraordinary objects in the world of horology; it requires neither manual winding nor batteries. It operates based on fluctuations in ambient temperature and atmospheric pressure. The mechanism is driven by a sealed capsule filled with a special gas. When the temperature changes by just 1°C, the gas expands or contracts, activating a pneumatic capsule that winds the mainspring and powers the clock. Such a minor temperature variation allows the Atmos clock to store enough energy to run for two full days. It winds itself continuously until it reaches maximum capacity. Theoretically, as long as the clock remains in a room with temperature fluctuations, it will run indefinitely without any manual intervention. Please examine the photographs carefully! They are part of the description. The clock will be securely packed in two boxes for shipping.