The automatic COSC-certified PF441 chronometer movement that this Parmigiani typical operates on offers a 55-hour power reserve, owing to its oscillating mass, which is in delicately engraved gold, and might be admired throughout the sapphire crystal caseback. And admire it you will, as it shows several of the greatest decoration https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/