Mueller® Hinged Knee Brace features a triaxial hinge to track your knee’s natural movement. The fitted sleeve slips on and provides maximum medial-lateral support of your weak or injured knee. Fits either knee.Mueller® Hinged Knee Brace offers maximum medial-lateral support without restricting your mobility. The triaxial hinge ensures proper tracking of your knee joint while the patella buttress helps stabilize and protect your kneecap. - Open patella and patella buttress help stabilize and protect your kneecap. - Slip-on sleeve and adjustable straps provide controlled compression and a custom fit. - Super strong triaxial hinge follows the complex motion of the knee resulting in near-normal motion that 2-hinge polycentric hinges simply cannot match.