X-SMALL - Women's Shoe Size 2.5-6 / Men's Shoe Size 1-4.5
SMALL - Women's Shoe Size 6.5-10 / Men's Shoe Size 5-8.5
MEDIUM - Women's Shoe Size 10.5-12.5 / Men's Shoe Size 9-11
LARGE - Women's Shoe Size 13-15 / Men's Shoe Size 11.5-13.5