More robust and lightweight than previous versions, the Nike Air Zoom Structure 21 Men's running shoe ensures stability and support that have made it one of the most popular models ever. The Flymesh material, softer and lighter, keeps the skin fresh while the Nike Zoom Air reactive cushioning on the forefoot ensures maximum elasticity under the foot. The one-piece Flymesh fabric ensures ideal breathability on the back of the foot. Despite the lighter materials, this type of Flymesh ensures solid support. Born from the union of Flywire and inner band on the arch, the Dynamic Fit technology offers stability that adapts to your foot. The two upper eyelets are Flywire cables, resistant and light, which attach to the laces for an ideal support when you tie the shoe. In addition, the elastic band wraps around the arch to prevent the foot from slipping into the shoe during the run. The wide, flat sole and two types of cushioning ensure maximum stability. The stiffer foam protects the inside of the arch, while the softer protects the outer side, for ideal impact protection and maximum stability during the race.