The automatic COSC-Licensed PF441 chronometer movement that this Parmigiani vintage operates on provides a 55-hour energy reserve, owing to its oscillating mass, which can be in delicately engraved gold, and may be admired through the sapphire crystal caseback. And admire it you might, because it displays a few of the https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/