Lorpen Women's Tri-Layer Light Overcalf Sock 38% primaloft eco polyester, 37% merino, 15% nylon, 10% lycra Trilayer design - synthetic next to the skin wicks moisture away to keep foot dry; middle layer is natural yarn that spreads out the moisture over a large surface; synthetic (nylon) is the outer layer for durability light cushion, over calf height, excellent moisture management, fast drying Machine washable, tumble dry, no bleach Made in Mexico