Thermoskin Elastic Ankle is anatomically designed and with no seams, the elastic support will comfortably contour to the shape of your ankle. It provides even compression and support for weak and injured ankles, while minimizing bunching. Measure around ankle joint. Small 6 1/4 -8 1/4, Medium 8 1/4 -10 1/4, Large 10 1/4-12 1/4, X-Large 12 1/4 -14 1/4.