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