The automatic COSC-Qualified PF441 chronometer movement that this Parmigiani common runs on provides a fifty five-hour electrical power reserve, owing to its oscillating mass, and that is in delicately engraved gold, and might be admired through the sapphire crystal caseback. And admire it you are going to, as it shows https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/