The automatic COSC-Licensed PF441 chronometer motion that this Parmigiani classic runs on offers a 55-hour electricity reserve, owing to its oscillating mass, which happens to be in delicately engraved gold, and may be admired from the sapphire crystal caseback. And admire it you might, mainly because it displays a number https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/