adidas Pure Boost X Women's Running Shoes Synthetic Rubber sole Engineered Mesh Upper - Provides breathability whilst conforming to the shape of the feet. Synthetic Sidewall Panels - Delivers a structurally sound upper, adding stability to the interior. Featherweight Sockliner - Adapts to the foot for customised fit and feel. Welded Overlays - Adaptive and dynamic in fit yielding optimal flexibility. 100% Boost Midsole - BOOST foam capsules compromise the midsole, functioning to lessen the loss of energy.