Flexible Nike Free technology puts biomechanic comfort and agility under every step in a training shoe that moves with you through circuits, sprints and squats. It's built from the ground up with a wide heel and solid base to stabilize lifts and strength training, with flywire-anchored laces providing a locked-in feel and a dynamic fit that support quick changes of speed and direction. An innovative 7/8 inner sleeve stretches, rebounds and breathes to keep your footing secure as your intensity heats up. Training: provides stability, cushioning and uninhibited range of motion for multiple exercises and activities Flywire cables integrate with the laces for secure, flexible lockdown at the midfoot Removable, cushioned insole allows for custom orthotics Nike Free sole with flex grooves in the tread mimics natural foot movement with every stride Textile and synthetic upper and lining/rubber and synthetic sole Imported