Visible through the caseback, the oscillating mass in the movement is delicately engraved. It can be made from eighteen-karat gold and decorated by hand using a barley grain sample, completed by guilloche A paragon of robustness and reliability, the forty mm Oyster case of The brand new GMT-Grasp II is https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/