The polished blue bi-directional rotating bezel is compelete using a dazzling orange GMT scale and helium-escape valve at 10 o'clock on the case. It requires the melting with the Uncooked material applying oxyhydrogen flame plus the crystallisation of your melted droplets to kind a cylinder. Graded nine within the Mohs-hardness https://www.watchesworld.com/top-10-dive-watches/