The Hydrogen Aero Road Socks uses the same VaporRize Hydrogen yarns used in our Hydrogen Vent Socks on the foot, but adds a rib-knit cuff that gives you an aerodynamic advantage over normal socks. It's like getting free speed for your legs. - 7" cuff height (size Medium) - PowerBand mid-foot arch supports the foot and secures the shape and fit where the foot needs it most. - Rib-knit cuff has an aerodynamic stripe pattern, providing a speed advantage without needing a special fabric to be sewn to the sock. This allows for the ultimate comfort in this high-performance category. - Targeted textured zone under forefoot reduces slip. - VaporRize Hydrogen yarns are extremely lightweight and soft against the skin, placing an emphasis on moisture transfer and minimizing friction. - Vented mesh toe channel helps to keep things light and airy within the shoe.