Under Armour Boys Undeniable Mid Crew Socks 65% Polyester, 24% Cotton, 8% Nylon, 3% Spandex Imported Left/right technology for true anatomical fit Embedded arch support helps reduce foot fatigue Arm our dry material wicks moisture, accelerates evaporation Arm our Block technology helps prevent growth of odor-causing bacteria Arm our fit support in the key arch and ankle zones for tighter, more secure fit