Our ENGAGE° foam is produced using recycled CO2 gas instead of the traditional chemical reactions used in other foams.This is a more eco-friendly production process than conventional methods. RECYCLED AND BREATHABLE UPPER YARN ensures great ventilation for those longer miles and ample space for toe splay during natural motion. Anatomically designed pressure free tongue removes pressure and stress from the top of the foot. Ortholite sockliner provide long-lasting comfort, excellent moisture management and a high breathability through open-cell,it utilizing 20% recycled content.