Seen from the caseback, the oscillating mass in the movement is delicately engraved. It is produced from eighteen-karat gold and decorated by hand having a barley grain pattern, finished by guilloche In the event your Omega has the text 'Master Chronometer' around the dial—as is noticed inside the Seamaster Diver https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/