The automated COSC-Licensed PF441 chronometer motion that this Parmigiani basic runs on offers a 55-hour power reserve, owing to its oscillating mass, and that is in delicately engraved gold, and can be admired with the sapphire crystal caseback. And admire it you can, because it displays several of the best https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/