Features Sock designed for athletes. Specific design for left and right foot, for a perfect fit. Breathable performance fabric to keep your feet dry Reinforced areas in the toe and heel. Flat seam to prevent chafing. Tight high top. Made of Spandex, Nylon and Polyester. Choose between the two sizes: S-M (37-40.5), M-L (41-45). Designed to keep the foot dry and prevent chafing. Composed of Nylon and Polyester, we were looking for synthetic materials that stand out for their strength, elasticity and quick drying. Another characteristic that influences quality is Spandex that helps it fit snugly to the foot, preventing it from moving. The reinforcement in the toe and heel, where we include a small percentage of cotton, makes them more resistant and gives a soft touch. Its differentiated design for each foot provides the support and comfort you need while you enjoy.