Body Glove 90174 Breathable Neoprene Ankle Support, Black, Medium Improves Joint Stability Contoured, Sized Fit Fully Lined, Smooth Interior Breathable, open-cell neoprene for comfort in hot conditions Contoured, sized fit Improves joint stability Fully lined, smooth interior Measure around ankle at smallest point. Medium fits 8-1/4-inch to 9-inch.