Aetrex Dress/Casual Socks with Copper Sole Technology are unsurpassed in comfort, performance and protection. Copper Sole Technology has been lab tested and clinically proven to help prevent bacteria, fungi and odor as well as improve skin texture and appearance. Copper ions are embedded in the CUPRON yarn to eliminate 99.9% of the bacteria and fungi in the sock, providing superior protection against odor that"s guaranteed for the life of the sock.