The automated COSC-Qualified PF441 chronometer movement that this Parmigiani vintage runs on offers a 55-hour power reserve, owing to its oscillating mass, that is in delicately engraved gold, and can be admired in the sapphire crystal caseback. And admire it you can, mainly because it shows many of the best https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/