The automated COSC-certified PF441 chronometer movement that this Parmigiani basic operates on provides a 55-hour electrical power reserve, owing to its oscillating mass, which happens to be in delicately engraved gold, and may be admired through the sapphire crystal caseback. And admire it you'll, because it shows a lot of https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/