It's a domed acrylic crystal deal with, leather-based strap, and a light-weight build that helps make this look at snug wear each day. Consider: Acrylic crystal just isn't as scratch-resistant as sapphire or mineral crystal; the leather band could possibly present wear speedier than expected. The nautical design is waterproof https://www.watchesworld.com/understanding-the-complex-world-of-chronometers/