The automatic COSC-Licensed PF441 chronometer motion that this Parmigiani typical operates on offers a 55-hour power reserve, owing to its oscillating mass, which is in delicately engraved gold, and may be admired through the sapphire crystal caseback. And admire it you will, since it displays a few of the best https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/