The automatic COSC-Qualified PF441 chronometer movement that this Parmigiani typical runs 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 will, because it displays many of the greatest decoration https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/