Smartwool Kids Oui Mademoiselle, Berry size XS wool Knee high sock with polka dots and stripes, supportive arch brace SmartWool inside for moisture, temperature, and odor control. Flat knit toe seam. Knee high height, non-cushion sole. 80% merino wool, 19% nylon, 1% elastane, washing machine and dryer friendly! Kid's Size XS=shoe size 6-8.5, S-shoe size 9-11.5, M=shoe size 12-2.5, L=shoe size 3-7