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