The automatic COSC-Qualified PF441 chronometer movement that this Parmigiani vintage runs on offers a fifty five-hour electric power reserve, owing to its oscillating mass, which can be in delicately engraved gold, and will be admired in the sapphire crystal caseback. And admire it you may, because it displays a number https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/