Tri density collar foam combines medial support with lateral flexibility
With stability where you need it, cushion where you want it, the Structure 25 supports you for long miles, short training runs and even a down-and-back before the day ends. It??s the stability you seek, loyal from the first tie-up, tried and trusted, with a midfoot system that??s fully supportive and more comfortable cushioning than before.
Lightweight polymers reduce overall mass without sacrificing structural integrity.