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