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