We've updated our patented Tubes system from the ground up to create the Tubes Sport. The technology provides unmatched comfort and cushioning through individually tuned tube structures that collapse and rebound as you walk. The design also provides incredible flexibility, making every stride smooth and efficient. Smaller, more rigid tubes on the inside area of the heel provide extra medial support to reduce pronation. A light weight mesh upper provides additional coolness and airflow, while the TPU stripes and mud guard provide stability.