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