The Superfeet Medium Arch signature shape adds comfort and stability to your shoes, helping to reduce stress on your feet, ankles, knees and back. Help to improve effeciency, reduce fatigue and support every step you take with the responsive EVOLyte carbon fiber cap. With an additonal thin layer Aerospring Rebound foam combined to deliver exceptional comfort and a smooth and efficient energy transfer. Through your gait from foot strike to toe off, they are made to replace the removable liner in moderate to tight-fitting shoes.