The automatic COSC-certified PF441 chronometer motion that this Parmigiani traditional runs on provides a fifty five-hour energy reserve, owing to its oscillating mass, that is in delicately engraved gold, and may be admired throughout the sapphire crystal caseback. And admire it you are going to, since it shows a lot https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/