Medium * Fits Circum. 13.5 - 15 * Elastic Support For Prevention Treatment & Rehabilitation Of The Knee * Thermoskin Elastics Can Expand Contract And Stretch And Are Made Of A High-grade Durable Material That Permits A Full Range Of Movement And Are Comfortable To Wear During A Range Of Activities * Anatomically Designed With No Seams This Four-way Stretch Support Combines Spandex With Hosiery Technology To Provide Protection And Support For Weak And Injured Knees