Leatt Moto Gpx Sport Neck Brace. The Leatt-Brace MOTO GPX Sport Neck Brace is an injection produced glass reinforced nylon or carbon fiber and kevlar neck brace system designed by medical professionals and motorcycle enthusiasts to help prevent severe injury occurring in the event of an accident. Leatt Moto GPX Sport Braces may help prevent the following injuries: Hyperflexion: extreme forward head movement. Hyperextension: extreme rearward head movement. Lateral Hyperflexion: extreme sideways h