The automatic COSC-certified PF441 chronometer motion that this Parmigiani vintage operates on offers a 55-hour electric power reserve, owing to its oscillating mass, that's in delicately engraved gold, and may be admired throughout the sapphire crystal caseback. And admire it you can, because it displays many of the greatest decoration https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/