Vibram Fivefingers Spyridon LS Barefoot Running Shoe - Women39;s Synthetic Minimalist 3.5mm Vibram rubber sole provides impact protection from stones and debris, while better allowing proper barefoot dynamics. Aggressive tread design delivers sure-footed grip in all directions Molded nylon mesh in midsole adds a "rock block" effect, dispersing impact over a wider area Stitched-in polyurethane insole protects skin and foot tissue during longer runs Coconut Active Carbon upper offers natural breathability