The Dials involve sunray and guilloche finishes, and they are always guarded by scratch-resistant sapphire crystals. Hooked up to the cases are buttery-smooth Barenia leather-based straps, typically in the colour of one's choosing. Be occasion appropriate: Bear in mind The essential rules: black leather-based strap for formal don, metallic strap https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/