The automatic COSC-Accredited PF441 chronometer movement that this Parmigiani traditional operates on offers a fifty five-hour electric power reserve, owing to its oscillating mass, that's in delicately engraved gold, and will be admired through the sapphire crystal caseback. And admire it you are going to, since it displays a lot https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/