The automatic COSC-certified PF441 chronometer movement that this Parmigiani common runs on provides a 55-hour power reserve, owing to its oscillating mass, which is in delicately engraved gold, and may be admired throughout the sapphire crystal caseback. And admire it you will, since it displays a lot of the finest https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/