NIKE HYPERSTRONG MOUTHGUARD WITH FLAVOR ORANGE Best in class flavor injection technology creates unique, delicious flavor combinations to encourage long, consistent use. Dual-density EVA construction which enables a more customizable fit while still maintaining the shape of its protective outer wall. Patented O-flow breathing channels for maximum oxygen intake to improve athletic performance. Rear drainage channels. 88% EVA/8% polypropylene/4% polyester. Imported. One size fits most.