Spira - Del Sol (White/Blue) - Women's: The Del Sol is ideal for neutral, faster runners who seek a lightweight and flexible performance shoe. A newly designed lightweight WaveSpring is located in the heel to reduce stress and fatigue while providing energy return. Upper is made of a soft, breathable mesh for a cool comfortable ride. The unique forefoot quad flex columns provide superior cushioning and flexibility. Two piece high abrasion rubber outsole for durability.