Cotton75%, Polyester fibre22%, Spandex3%. Medium fits women's socks size 4.5-7 (US). 5 pairs per pack. MESH VENTILATION ZONE - Precision knit, breathable fabrics can better wick perspiration, keep feet dry and make outdoor activities easier and more enjoyable. FULLY CUSHIONED - Thickened toes and heels, high density, high elasticity, can ease the impact, reduce friction, effectively protect your feet from the blisters, while providing shock absorption and durability. 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 ideal for trekking, walking, running, camping, hiking, cycling and other outdoor activities.