Noticeable from the caseback, the oscillating mass of the motion is delicately engraved. It's constructed from eighteen-karat gold and decorated by hand having a barley grain sample, done by guilloche So if your Omega has the text ‘Learn Chronometer’ on the dial—as is witnessed On this signature Omega Seamaster Diver https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/