Mid weight cushioned sock. Merino wool cushioing provides shock absorption. Antimicrobial qualities. Flat toe seam construction to help prevent blisters. 100% Nylon leg sheds water and does not flap. Air vents to upper to help keep feet cool. Arch grip section and Y heel for optimum fit. Lycra for stretch and recovery. 48% Wool, 48% Nylon and 4% Lycra