The automatic COSC-Licensed PF441 chronometer motion that this Parmigiani vintage runs on provides a 55-hour energy reserve, owing to its oscillating mass, that's in delicately engraved gold, and can be admired with the sapphire crystal caseback. And admire it you are going to, as it displays a few of the https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/