Noticeable in the caseback, the oscillating mass with the movement is delicately engraved. It can be made out of 18-karat gold and decorated by hand using a barley grain pattern, performed by guilloche A paragon of robustness and reliability, the forty mm Oyster case of the new GMT-Grasp II is https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/