Design: Engineered mesh with tighter woven fabric in high wear areas to give you better coverage when the outdoor elements turn for the worse The upper is made of engineered mesh with open holes for better breathability Flywire technology integrates with the laces to help secure your midfoot Less rubber along the outsole creates a smooth transition from road to trail while preserving the full-length React midsole In-Shoe Comfort: Nike(R) ReactX foam midsole is engineered to reduce its carbon footprint by at least 43% in a pair of midsoles due to reduced manufacturing process energy compared to prior Nike(R) React foam Durability & Traction: Rubber wraps around the front of the shoe to provide extra durability Generative traction pattern combined with rubber in the forefoot provides extra grip for technical trails and a smooth ride for the road