The automated COSC-Licensed PF441 chronometer movement that this Parmigiani classic runs on provides a 55-hour electric power reserve, owing to its oscillating mass, which is in delicately engraved gold, and may be admired from the sapphire crystal caseback. And admire it you are going to, as it displays several of https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/