The automatic COSC-Qualified PF441 chronometer motion that this Parmigiani typical runs on offers a 55-hour 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 may, as it displays a lot of the best https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/