PEDS Boys Endur LowCut Socks Black with Color Medium 4 Pairs 38% Polyester, 30% Cotton, 29% Nylon, 3% Lycra Spandex Imported Machine Wash Coolmax xtralife fabric lasts longer and keeps feet dry, cool and comfortable Lycra fiber offers the ultimate in comfort and fit The perfect hole proof sock Endur technology-constructed to last up to 6X longer than our regular cotton blend socks Satisfaction guaranteeif you are not completely satisfied with your PEDS product, simply return them to us for replacement