The GEL CHALLENGER 13 tennis shoe creates the stability you need when you're covering the baseline, so you can keep your mind focused on controlling the point. The shoe's supportive upper keeps your feet locked in on the shoe's platform. It creates a reinforced feel during volleys or when you're dropping back to track down deep lob shots. WINGWALL technology is placed in the sidewall to improve stability during side to side movements. This feature offers good support, so you can step into your shot and stroke the ball with more pace.