The automatic COSC-Accredited PF441 chronometer movement that this Parmigiani common operates on provides a 55-hour electrical power reserve, owing to its oscillating mass, that's in delicately engraved gold, and can be admired in the sapphire crystal caseback. And admire it you can, since it shows some of the finest decoration https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/