Fast acceleration, cutting, jumping and sudden stops put the ankle and calf under stress. The Sport Compression Socks Ball and Racket target these areas with special compression zones to improve agility and stability. The distinctive taping zone surrounds the ankle in a figure eight to improve stability, body awareness and enhance coordination. The muscle toning zone stimulates calf muscles and reduces tiring muscle vibrations. The padded toe, forefoot and heel zones provide a shock absorbing effect. The cut-out in the area of the Achilles tendon prevents uncomfortable pressure or friction. The soft knit is highly breathable and durable, easy to machine wash and tumble dry. Size is determined by shoe size: Small: men 3.5 - 6.5, women 4.5 - 7. Medium: men 7 - 9.5, women 7.5 - 10.5. Large: men 10 - 12.5, women 11. X-Large: men 13 - 15.5, women N/A. Material: Knit Fabric.