The automatic COSC-Licensed PF441 chronometer movement that this Parmigiani common runs on provides a fifty five-hour power reserve, owing to its oscillating mass, which is in delicately engraved gold, and might be admired with the sapphire crystal caseback. And admire it you are going to, as it shows a lot https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/