ULTRABOOST UNCAGED SHOES-Responsive, supportive and flexible, these woMen's running shoes charge every step with endless energy. The shoes have a full-length boost? midsole that works with the STRETCHWEB outsole to harness and release energy with every step so you can run further with less fatigue. TORSION SYSTEM? in the midfoot pairs with the sock-like fit of the Adidas Primeknit upper to support your foot's natural flex from heel to toe. With a Continental? Rubber outsole that provides traction in all conditions.