Use these booties during classes and rehearsals. They are designed for dancers. The filling is 100% Polyester, the shell is 100% Nylon, and it has a cushioned heel. Not recommended for outdoor use. Sizing: XS (US 13.5 - 1.5), S (US 4 - 6), M (US 6 - 8), L (US 8 - 10), XL (US 10 - 12)