Noticeable throughout the caseback, the oscillating mass on the movement is delicately engraved. It is made from 18-karat gold and decorated by hand that has a barley grain pattern, done by guilloche The Diver 300M is offered in steel or combinations of metal and yellow or Sedna gold, which has https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/