Noticeable throughout the caseback, the oscillating mass from the movement is delicately engraved. It is produced from 18-karat gold and decorated by hand that has a barley grain pattern, completed by guilloche A paragon of robustness and dependability, the forty mm Oyster scenario of the new GMT-Master II is confirmed https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/