Seen with the caseback, the oscillating mass with the motion is delicately engraved. It's produced from 18-karat gold and decorated by hand using a barley grain sample, carried out by guilloche A gold Variation includes a black dial and black leather strap, in addition to an 18-karat gold pin-buckle All https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/