The automatic COSC-Licensed PF441 chronometer movement that this Parmigiani traditional operates on offers a 55-hour energy reserve, owing to its oscillating mass, which is in delicately engraved gold, and may be admired throughout the sapphire crystal caseback. And admire it you might, as it displays a lot of the best https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/