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