The Dials consist of sunray and guilloche finishes, and are usually shielded by scratch-resistant sapphire crystals. Attached to the circumstances are buttery-clean Barenia leather straps, often in the color of one's choosing. Impressed by British pilot’s watches in the seventies, Hamilton’s Khaki Aviation has every one of the rugged fashion https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/