The GEL-RESOLUTION™ X tennis shoe creates advanced comfort for players who like to control the game from the baseline. DYNAWALL™ technology in the midsole now extends into the heel for added stability during lateral movements. It's a functional feature that's effective when you're running covering both sides of the baseline. DYNALACING™ technology has been strategically designed to hold when extra support is needed. This allows you to experience a locked-in feel when you're making quick transitions. There's also a two-piece midsole design that helps improve stability when your foot lands on the court. Lastly, the higher medial collar helps prevent ankle twisting when making abrupt cuts back and forth.