The automated COSC-certified PF441 chronometer motion that this Parmigiani common runs on provides a 55-hour power reserve, owing to its oscillating mass, which is in delicately engraved gold, and can be admired with the sapphire crystal caseback. And admire it you'll, mainly because it shows several of the finest decoration https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/