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