Built to Perform The Zelos Ankle Length Sock has been designed to keep your feet cooler & dryer for longer. COOLMAX yarns aid with moisture management, wicking away excess moisture from the foot to keep you more comfortable during workout & training sessions. Mesh zones are strategically placed on the top of the foot to aid ventilation & breathability. Designed with the Runner in Mind The Zelos Sock has been designed by runners, for runners. The heel & toe has been reinforced to enhance durability, while hand linked toe seam add comfort in sensitive areas & prevent blisters. Arch support zones & Y-stitched heels offer a supportive fit, while shaped anti-stress cuffs allow freedom of movement where you need it most.