The automated COSC-Qualified PF441 chronometer motion that this Parmigiani traditional operates on provides a 55-hour energy reserve, owing to its oscillating mass, that is in delicately engraved gold, and will be admired through the sapphire crystal caseback. And admire it you may, as it shows a few of the finest https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/