THORSTEN - ONYX Black Ceramic Wedding Ring with Black Carbon Fiber Inlay and Polished Beveled Edges Comfort Fit Lightweight Durable Wedding Band - 8mm Hypoallergenic, Durable and Heat Resistant Black Ceramic Comfort Fit Great For Both Men & Women Great Wedding Ring or Promise Ring Free Shipping, Free Lifetime Warranty, Free Lifetime Sizing Carbon Fiber is made up of organic polymers, characterized by long strings of molecules bound together by carbon atoms.