Visible throughout the caseback, the oscillating mass of the movement is delicately engraved. It's comprised of eighteen-karat gold and decorated by hand using a barley grain sample, finished by guilloche In the event your Omega has the terms 'Grasp Chronometer' around the dial—as is observed during the Seamaster Diver 300M—you https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/