This is the Momentum Steelix Black-ion Watch with Nylon Nato Band All Options Features: Solid 316L stainless steel case Screw back, screw-down crown Rated to 660FT/ 200M Case diameter: 44mm Case diameter including crown: 47.99mm Momentum&';s version of the popular Nato" band style Band width: 22mm Heat-tempered, anti-glare mineral crystal (optional scratch-resistant sapphire crystal) Simple. Reliable. Legible. Steelix is now available in a Black-ion plated steel case. Steelix is our ultra-tough budget field watch. The 44mm case is machined from a block of solid 316L stainless steel and packed with all the features Momentum is known for. Inspired by the military, the "Nato" band was an essential part of the British military uniform during the Cold War. Today, it&';s still tough and ready for any adventure. Really tough on your watch? Consider upgrading to an ultra-hard, sapphire crystal. This is dramatically more scratch-resistant than regular mineral glass and virtually impossible to scratch, ensuring a crystal-clear view of the time, year after year!