Obvious from the caseback, the oscillating mass of your movement is delicately engraved. It's created from eighteen-karat gold and decorated by hand with a barley grain sample, carried out by guilloche If your Omega has the text 'Grasp Chronometer' around the dial—as is noticed during the Seamaster Diver 300M—you can https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/