The automatic COSC-certified PF441 chronometer motion that this Parmigiani basic operates on provides a 55-hour electric power reserve, owing to its oscillating mass, that's in delicately engraved gold, and can be admired through the sapphire crystal caseback. And admire it you'll, as it shows a number of the greatest decoration https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/