The automated COSC-certified PF441 chronometer movement that this Parmigiani classic operates on provides a fifty five-hour electric power reserve, owing to its oscillating mass, which can be in delicately engraved gold, and will be admired through the sapphire crystal caseback. And admire it you may, since it displays a lot https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/