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