Seen in the caseback, the oscillating mass of your motion is delicately engraved. It really is created from 18-karat gold and decorated by hand with a barley grain pattern, accomplished by guilloche So When your Omega has the phrases ‘Master Chronometer’ over the dial—as is noticed During this signature Omega https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/