The automatic COSC-certified PF441 chronometer movement that this Parmigiani basic runs on offers a 55-hour power reserve, owing to its oscillating mass, which is in delicately engraved gold, and may be admired in the sapphire crystal caseback. And admire it you'll, as it displays a number of the very best https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/