These classic crew socks from Zoe & Zac feature all-over soft cotton construction, reinforced toe seams for durability, extra ribbing around the top to keep them in place, and reinforced heels for the perfect fit. 75% Cotton, 24% Nylon, 1% Spandex. S/M fit kids shoe sizes 5- 9. M/L fit kids shoe sizes 9 - 3.