Synthetic-and-mesh Engineered mesh upper improves airflow - FLYTEFOAM Technology - Provides lightweight cushioning Anatomically shaped toe box - GUIDESOLE Technology - The curved sole design and stiff forefoot of our GUIDESOLE technology reduce ankle flexion and provide a shock-absorbent landing zone to lessen fatigue of other leg muscles and increase runner efficiency. Solution Dye Sockliner - Sockliner is produced with a solution dyeing process that reduces water usage and carbon emissions