The automated COSC-Qualified PF441 chronometer movement that this Parmigiani vintage operates on offers a fifty five-hour electrical power reserve, owing to its oscillating mass, and that is in delicately engraved gold, and will be admired through the sapphire crystal caseback. And admire it you can, as it shows a number https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/