McDavid 422 Dual Disc Adjustable Hinged Sports Rehabilitation Knee Support/Brace This Dual Disk Hinged Knee features two wider more stable hinges than standard knee braces. It incorporates our dual disk hinge with a floating pivot point to better accommodate the natural gliding action of the knee. The wider arms help dampen forces more efficiently. The neoprene sleeve provides therapeutic warmth while a sewn-on patellar buttress aids in patellar tracking. It also features a long 3/16 thick neoprene sleeve with nylon facing on both sides. Polycentric hinge offers advanced support over simple hinged brace. Includes hyperextension stops. Fits right or left knee WARNING Do not apply over open wounds or if you have a susceptibility to dermatitis Measure around knee cap (inches) Small = 30-36cm (12-14inches)Medium = 36-38cm (14 -16inches)Large = 38-43cm (15 - 17inches)X-Large = 43-51cm (17-20inches)XX-Large = 51-56cm (20 - 22inches) Model - 422R-BK