The automatic COSC-Qualified PF441 chronometer motion that this Parmigiani typical runs on offers a 55-hour electrical power reserve, owing to its oscillating mass, which happens to be in delicately engraved gold, and can be admired with the sapphire crystal caseback. And admire it you will, because it shows some of https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/