The automated COSC-Licensed PF441 chronometer motion that this Parmigiani classic operates on provides a 55-hour power 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, since it displays many of the best decoration https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/