The Nike Epic React Flyknit is built for extreme comfort that can last as long as your run. The one-piece Flyknit upper forms to your foot and flexes with it, incorporating the tongue as one piece. Nike React foam cushioning is responsive and lightweight, durable and soft. These opposites attract to enhance your feeling of moving forward, while letting you take your fun on the run. A heel shelf stabilizes the back of your foot to help keep your heel from rocking as your foot lands. And synthetic suede heel lining helps prevent slippage and blisters.