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