The automated COSC-Qualified PF441 chronometer movement that this Parmigiani basic operates on offers a 55-hour energy reserve, owing to its oscillating mass, and that is in delicately engraved gold, and may be admired from the sapphire crystal caseback. And admire it you may, since it displays several of the best https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/