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