Extreme energy return, mile after mile. ESM Techfit upper provides natural, flexible support and a seamless, sock-like fit. Midfoot tongue wraps firmly around the midfoot for enhanced fit and lockdown. External heel counter for a snug, comfortable fit. TPU pellets in the Boost midsole create a soft, responsive ride. FORMOTION decoupled heel system adapts and moves with your individual running style. Continental Rubber and adiWear non-marking rubber in the outsole increase traction in both dry and wet conditions. Wt. 11.1 oz.