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