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.