Small * Fits Knee Circum. 12.5 - 13.25 (measurement Taken Just Under The Knee Cap While Knee Is Slightly Bent) * Thermal Support For Prevention Treatment & Rehabilitation Of The Knee * Provides Protection And Support Against General Wear And Tear Including Sprains Strains And Twisted Knees * Anatomically Shaped In 3 Pieces For More Comfort And A Better Fit * Thermoskin Increases Elasticity Of Muscles Tendons And Ligaments To Reduce The Risk Of Injury When Under Stress And Strain * Clinically Proven To Increase Surface Skin And Subcutaneous Temperature Between 2-3 Degrees F The Optimal Level To Make Tendons And Muscles More Pliable And Elastic To Provide Optimal Muscle Function