The automatic COSC-certified PF441 chronometer motion that this Parmigiani traditional operates on provides a 55-hour energy reserve, owing to its oscillating mass, and that is in delicately engraved gold, and may be admired in the sapphire crystal caseback. And admire it you'll, since it shows some of the finest decoration https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/