The automated COSC-Qualified PF441 chronometer movement that this Parmigiani common runs on provides a 55-hour electrical power reserve, owing to its oscillating mass, which happens to be in delicately engraved gold, and will be admired in the sapphire crystal caseback. And admire it you will, as it shows a few https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/