The case is 60% nylon and 40% carbon mixed into strong plastic and they actually mold that to the steel case and screw screw it in. Bezel is 100% carbon on steel. It's a cool watch material for a case. The comfort of these is always top notch. Accurate nice movements as well. Date wheel moves in both directions. Solid bezel action. Might be on par with Rolex actually. I like it!