Seirus Hyperflex Nuclear Knee: Hyperflex knee brace is especially designed to give protection to your knee. It has loads of features such as: a hyperflex insert, breathable Neoprene, superior compression and warmth from closed cell neoprene, a padded patella locator relieves pressure and helps prevent patellar injury. The Hyperflex Nuclear Knee has additional features such as: technical locking, dual pivot, metal hinges to help prevent hyperextension, pull on loops and Velcro adjustable support straps. Small 13.25 "-14.5 " Medium 14.75 "-16 " Large 16.25 "-17.5 " XLarge 17.75 "-19 " XXLarge 19.25 " Seirus Hyperflex Nuclear Knee | Black | Small | Christy Sports