Designed to provide comfortable even compression. Size Selection: For left or right foot, measure around the heel and the instep. Small: 10-12.5 inch (25.4-31.8 cm). The Ace Trademark is your assurance of superior quality, support and comfort. Trusted brand since 1918. Anatomical shape for optimal fit and joint protection. Fits comfortably in shoe. Breathable, dual-stretch power knit materials for comfort. Comfort panel reduces bunching behind the heel. The Ace Knitted Ankle Support is designed to provide support to stiff, weak or injured ankles. Wear during activities which lead to discomfort. Provides light compression, support and therapeutic heat retention to help relieve symptoms associated with minor sprains, strains and arthritis. Made in China for 3M.