Extremely lightweight and incredibly breathable comfort are yours when hiking in these Darn Tough Hiker Micro Crew Lightweight Socks. Mesh panels along the top of the foot increase the airflow. And a strong, thin layer of cushioning-including along the Achilles-makes these a comfortable everyday option. 49/47/4 nylon/Merino wool/LYCRA spandex for all-season performance Mesh panels on top of foot for increased breathability Moisture-wicking and fast-drying comfort Naturally antimicrobial to repel bacteria and odor True Seamless undetectable seam fusiona |you simply won't feel it Fine-gauge knitting for durability without excess bulk Lightweight cushioning underfoot that also extends over Achilles Micro crew height goes just above your hiking boots Performance fit won't slip or bunchSizing Details Small: Fits Women's shoe size 4.5-7 Medium: Fits Women's shoe size 7.5-9.5 Large: Fits Women's shoe size 10-11.5