Keen (Shoes) Accessories Women's Kanga Lite Crew Socks 49% Merino Wool, 48% Nylon, 3% Lycra Spandex Made in US Y-heel pocket to keep sock in place Left and Right design for optimal Fit Seamless toe in flex zone to avoid bunching Contour arch support for comfort Impact cushioning in key areas Y-heel pocket to keep sock in place