The Adidas Women’s Ultraboost 21 Running Shoe is designed for a harmonious balance of weight, cushioning, and responsiveness. The sock-like fit and Adidas Primeknit+ upper provide a comfortable and supportive fit, while the Stretchweb outsole with Continental rubber provides incredible energy return. The Primeblue fabric is made from recycled ocean plastic and the lace closure provides a secure fit. The new Torsion System provides a 15% increase in forefoot bending stiffness for a more responsive run.