The automatic COSC-Qualified PF441 chronometer motion that this Parmigiani traditional runs on provides a 55-hour electrical power reserve, owing to its oscillating mass, and that is in delicately engraved gold, and may be admired through the sapphire crystal caseback. And admire it you might, mainly because it shows some of https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/