After developing the cycling version of the Pro Racing Ultralight sock for Joachim Purito Rodriguez we decided our elite runners also deserved the same lightning-fast coolness. Featherlight the 9-gram Racing Sock Ultralight Run provides an unparalleled second-skin feel & exceptional comfort thanks to ultra-soft mesh fabric. Ventilation is second-to-none so that your feet stay fresh & dry at all times. Specific fibres act as hot spot preventers to ensure your soles do not burn up no matter how long they batter the pavement. Cleverly-placed 3D. Dots on the internal malleolus protect the bone from impact for runners who tend to clip it with the opposing foot when fatigued. Targeted compression boosts blood flow while the toe box is slightly reinforced to reduce the risk of beaten-up toes & blue nails during long intense efforts. If you are racing through the Saharian desert or facing a heat wave in Boston this cooling white running sock is your weapon of choice. KEY BENEFITS Hot spot prevention thanks to specific fibres in targeted areas which stop your feet from feeling hot & burning up during running. Maximum thermoregulation thanks to mesh ventilation panels woven directly into the fabric helping keep your feet fresh & cool through fast sweat-evacuation. Exceptional 360° breathability & ventilation thanks to ultra-thin fibres & mesh panels keeping your feet fresh & dry even in hot conditions.