The automatic COSC-Accredited PF441 chronometer movement that this Parmigiani classic operates on offers a 55-hour electrical power reserve, owing to its oscillating mass, which can be in delicately engraved gold, and may be admired in the sapphire crystal caseback. And admire it you can, as it displays a few of https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/