The Bort AchilloStabil Ankle Support is a revolutionary three-dimensional form-knitted dual-tension elastic bandage that helps against acute and chronic achillodynia, and postoperative ruptures. Provide pressure relief for your achilles tendon. Ankle Circumference -Small = up to 8.3". Medium = 8.3" - 9.1".Large = 9.1" - 9.8".