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