Lorpen Men's Tri-Layer Midweight Hiker Crew Sock 50% Primaloft Eco Polyester/ 25% Merino/ 15% Nylon/ 10% Lycra Imported Men's trilayer midweight hiker Trilayer knit technology layers both synthetic and natural yarns in a way that improves moisture management, comfort and durability 50% Primaloft Eco Polyester yarn, 25% merino, 15% nylon, 10% lycra Primaloft blends 50% virgin fibers and 50% recycled fibers to create a high loft performance insulation. Crew height, medium full cushion