Use these warm - up booties between classes and rehearsals. They are perfect for dancers. The sizes range from XS (fits US 13.5 - 1.5) to XL (fits US 10 - 12). If you plan to wear pointe shoes with them, take the next size up from your normal shoe size. They have a 100% Polyester filling for warmth, a cushioned heel, and a 100% Nylon Shell.