Smartwool Kids Ski Racer Socks, black/graphite size L 100% Wool All day warmth and comfort, in this light full-cushioned ski sock for kids Breathable Smartwool fibers, washer and dryer friendly Kid's size S-shoe size 9-11.5, M=shoe size 12-2.5, L=shoe size 3-9 62% Merino wool, 37% nylon, 1% elastic. Washer and Dryer friendly