Use these booties between dance classes and rehearsals. Ideal for dancers. They have 100% Polyester filling for warmth and comfort, a cushioned heel, and a 100% Nylon Shell. Sizing: XS (US 13.5 - 1.5), S (US 4 - 6), M (US 6 - 8), L (US 8 - 10), XL (US 10 - 12). If wearing with pointe shoes, take the next size up from your normal shoe size. Not recommended for outdoor use.