As evidenced in the name, the Air Zoom Structure provides the needed guidance and reorientation of the foot that an overpronator needs. BRS 1000 carbon rubber is placed strategically in high-wear areas of the outsole to keep the shoe in top shape for hundreds of miles, and the dynamic FlyWire Cables connected to the lacing system help engineer a custom-fit feel. Testers enjoyed the comfort provided by the engineered mesh upper during their long training sessions.