Smartwool Kids Skyscape, Peony size S wool The best designs for kids come from, well, kids. Designed by fifth graders who know what it means to be a mountain kid. Knee height, non-cushioned sole. 78% merino wool, 21% 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 3-8