Carhartt BA66 Boys' Cold Weather Boot Sock, brown. 58% Acrylic, 14% Nylon, 13% Polyester, 10% Wool, 1% Spandex, 4% Other Fibers Our signature style is fully cushioned to keep boys warm and protected from the elements Reinforcement throughout the sole extends the life of the sock and adds protection in the highest abrasion areas Ankle vents reduce bulk so you don't have to sacrifice comfort for warmth M is sock size 7-8.5 (shoe size 9-2.5) L is sock size 9-11 (shoe size 3-9) Made in the USA!