Nike Men's React Miler 2 Running Shoes Blue/Thunder Size 8 D Medium USThe upper places engineered mesh in key zones to keep it lightweight breathable and durable. A band at the midfoot tightens around your foot when you lace up providing a snug fit. A stiff piece around the heel offers extra support. Nike React technology is a responsive foam that creates a smooth ride. A rubber sole creates durability and traction for high mileage training. High abrasion rubber is placed in areas that get the most wear.