Material and Fabric: Top layer: Polyester fiber 92.6%, diene elastic fiber 7.4%. Bottom layer of upper: Polyester fiber 97.9% spandex 2.1%. XS Sole length : 11.5 cm, age 0-6 months;S Sole length : 12.5 cm, age 6-12 months;M Sole length : 13.5 cm, age 12-18 months;L Sole length : 14.5 cm, age 18-24 months;XL Sole length : 15.5 cm,age 24-30 months.