The automated COSC-Accredited PF441 chronometer movement that this Parmigiani basic runs on offers a 55-hour energy reserve, owing to its oscillating mass, which can be in delicately engraved gold, and can be admired in the sapphire crystal caseback. And admire it you are going to, since it shows a number https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/