Celine lin Boy's Stripes Simple Children Boy Sport Socks Students Crew Socks,10-Pair 100% Cotton Materail: 85% cotton,15% spandex Size S : 15cm - 19cm ( 5.90''-7.48'' ) ,US 6.5 M - 10.5 M ,UK 5.5 M - 9.5 M ,Euro 22.5 M - 27.5 M ,advise 3-6 years old kids to wear Size M : 19cm - 23cm ( 7.48''-9.06'' ) ,US 10.5 M - 13.5 M ,UK 9.5 M - 12.5 M ,Euro 27.5 M - 31.5 M ,advise 7-12 years old kids to wear Quantity:10-pair one set Crafted from the finest combed cotton with attention to the very smallest of details:Pefect toe seaming,Stay up comfort cuff.Quality is important.If you have any problems with our socks, please let us know and we would be happy to work with you to resolve the problem. We hope you enjoy your purchase!