The T3 Ultra Light Mini Sock features 3 separate layers of fibers that work together for comfort, support, and moisture management. A layer of TENCEL(R) provides a layer that is soft to the touch and comfortable against the skin. It is a fully biodegradable fiber that is made from trees from sustainable farms. The COOLMAX(R) layer works to move perspiration away from the body, and through the fabric, where it can evaporate quickly, allowing the wearer to feel cooler and more comfortable. Lastly, a layer of Nylon and Ea. LYCRA(R) adds durability and ensure these socks stay up in your shoes without slipping down to your toes.These 3 Layers make the T3 Ultra Light Mini Sock perfect for biking, running, or any active sport. With these socks your feet will stay dry and comfortable all day long. Features: - TENCEL(R) fibers provide a soft comfortable layer against the skin - COOLMAX(R) fibers wick moisture away from the foot - 10% Ea. LYCRA(R) all throughout the sock means no slipping or bunching up - Mesh Instep that minimizes bulk on the top of the foot and promotes heat and moisture release - Non-cushioned for reduced weight - Flat Knit Toe Seam means no irritation on your toes while you run - Women's specific fit (narrower heel and forefoot) - Mini height - 36% Tencel(R), 35% Coolmax(R), 18% Nylon, 10% EA.Lycra(R), 1% Modal(R) Sizing (Women's US Shoe Size): - Small: W 4-6.5 - Medium: W 7-9.5 - Large: W 10+