The automated COSC-Accredited PF441 chronometer motion that this Parmigiani vintage runs on offers a 55-hour energy reserve, owing to its oscillating mass, that is in delicately engraved gold, and might be admired from the sapphire crystal caseback. And admire it you will, because it displays several of the greatest decoration https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/