The automated COSC-Qualified PF441 chronometer movement that this Parmigiani classic operates on offers a fifty five-hour electricity reserve, owing to its oscillating mass, that's in delicately engraved gold, and can be admired from the sapphire crystal caseback. And admire it you'll, as it shows a few of the finest decoration https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/