The automatic COSC-Qualified PF441 chronometer motion that this Parmigiani basic runs on provides a 55-hour power reserve, owing to its oscillating mass, that's in delicately engraved gold, and may be admired through the sapphire crystal caseback. And admire it you will, mainly because it displays a few of the finest https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/