Size Chart Description 77% Polypropylene/17% nylon/3% elastic/3% lycra® spandex wicking yarn Moisture, odor, and blister control Antimicrobial Breathable mesh Arch compression Size Chart Small: For Shoe Sizes: YOUTH 12-5 and LADIES 4-7 Medium: For Shoe Sizes: MEN 6-9 and LADIES 7-10 Large: For Shoe Sizes: MEN 9-12 and LADIES 10-13 Extra Large: For Shoe Sizes: MEN 12-15 and LADIES 13+