it was the first air technology developed at Nike, and it changed the way people thought about cushioning. It remains a standard for impact protection more than 20 years after its creation. The Nike Air made from pressurized gas inside a tough yet flexible urethane plastic capsule. The large molecules of gas prevent it from escaping the bag. The Air-Sole units are encapsulated in the midsole beneath the heel, forefoot, or in both locations depending on the shoe and the needs of the athlete for whom the shoe was designed. The Air-Sole works to cushion the foot by compressing and reduces the force of the impact and then immediately recovers its original shape, ready for the next impact.