adidas Ultra Boost Women's Running Shoes Engineered Mesh Upper - Incorporating differentiating level of thickness to deliver precision support and adaptability whilst being highly breathable. Primeknit - Carefully engineered to naturally expand with your foot while you run to give you a more comfortable fit and help reduce irritation. 100% Ultra Boost Midsole - Packing 3,000 energy capsules together the Ultra Boosts boasts 20% more capsules than any other boost incarnation to date. TORSION SYSTEM - Allows for more independent movements between the heel and forefoot, giving runners superior stability and a smooth, controlled run. STRETCHWEB Rubber Outsole - Energy-harnessing outsole that adapts and stretches with your foot strike and movement.