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