The automatic COSC-Qualified PF441 chronometer movement that this Parmigiani typical operates on provides a 55-hour electrical power reserve, owing to its oscillating mass, that is in delicately engraved gold, and might be admired through the sapphire crystal caseback. And admire it you may, as it displays several of the finest https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/