Cotton78%, Polyester fibre20%, Spandex2%. Medium fits women’s socks size 4.5-7 (US). MOISTURE CONTROL - Walk all day long and no need to worry about moisture due to our Exclusive Moisture Wicking Management, breathable and fast drying, keeping your feet cool and dry. FULLY CUSHIONED - With thickened towel bottom design to made our hiking socks more soft and comfortable, which reduce foot friction and relieve foot fatigue, effectively protecting your feet from shear and painful blisters. EXCELLENT ELASTICITY - Elasticized arch brace, good flexibility, to avoid the rotation of the sock during the movement; elastic ribbed cuffs, not tight or loose, durable and comfortable. HIGH PERFORMANCE ATHLETIC SOCKS - FEIDEER outdoor recreation socks are comfortable, breathable, moisture-wicking cotton socks, ideal for trekking, walking, running, camping, hiking, skiing, cycling and other outdoor activities.