BOOST midsole Continental Rubber outsole Lace closure Every detail accounted for. The proven adidas Ultraboost running shoes are built for each run on your training plan. Hundreds of BOOST capsules are fused together for incredible energy return. An adidas PRIMEKNIT upper hugs the foot to enhance every move. The Linear Energy Push system integrates with the outsole to increase stability for a responsive feel. This shoe's upper is made with a high-performance yarn which contains at least 50% Parley Ocean Plastic - reimagined plastic waste, intercepted on remote islands, beaches, coastal communities and shorelines, preventing it from polluting our ocean. The other 50% of the yarn is recycled polyester.