Childrens/Kids Little Boys Plain School Socks With Lycra (Pack Of 3) Cotton, Polyamide, Lycra Elastane Premium quality school socks. Long lasting and excellent fit socks. Fibre: 80% cotton, 17% polyamide and 3% lycra elastane. Machine washable. US Sizes: 4-6.5 (Age: 1-2 years), 7-9.5 (Age: 2-4 years), 10-13.5 (Age: 5-7 years), 13.5-4.5 (Age: 8-12 years), 5-7 (Age: 13+ years).