Reaction® Knee Support Medium / Large Pull-On / Hook and Loop Strap Closure 18-1/2 to 23-1/2 Inch Circumference Left or Right Knee (746725_EA) 1/EAProgressive pain relief: The elastomeric web design helps to reduce pain by dispersing energy across the knee. Elastomeric web: Acts to dynamically stabilize the patella on all sides, bringing the patella into proper tracking position to reduce pain for those with general patellofemoral instabilities Sustained comfort: The open framework of the elastomeric web, in combination with the mesh backing, creates a comfortable fit and a breathable solution