The automated COSC-Licensed PF441 chronometer movement that this Parmigiani common operates on offers a 55-hour electric power reserve, owing to its oscillating mass, which is in delicately engraved gold, and may be admired from the sapphire crystal caseback. And admire it you'll, because it shows many of the finest decoration https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/