The automatic COSC-Qualified PF441 chronometer motion that this Parmigiani traditional operates on offers a fifty five-hour electrical power reserve, owing to its oscillating mass, and that is in delicately engraved gold, and may be admired from the sapphire crystal caseback. And admire it you are going to, since it shows https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/