The automatic COSC-Qualified PF441 chronometer motion that this Parmigiani classic runs on offers a 55-hour power reserve, owing to its oscillating mass, which is in delicately engraved gold, and might be admired with the sapphire crystal caseback. And admire it you might, since it displays some of the finest decoration https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/