Clarks Tri Allie is made of a breathable woven material and composed of technology that contributes to the natural movements of the foot. The trigenic system on which the sole is built is an ultra-light reactive system that is built on the normal gait of the foot. Supported by specially developed technology, the shoe contributes to your normal gait and supports you with every step. The shoe is closed and fastened with a simple Velcro closure across the foot.