McDavid 429 Pro Stabilizer Knee Support / Brace Hinged For Maximum Protection The McDavid 429 Hinged Knee Brace benefits from using lightweight materials and design including aircraft grade aluminium gears that accommodate the natural gliding action of the knee. Exceptionally high quality hinged knee brace offering maximum protection. Suitable for moderate to major ligament injuries. Solid metal stays down the side with a geared polycentric hinge and hyperextension stop. Ideal for skiing and other high risk activities. What size do I need? Measure around the middle of the knee. 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) Colour Black Size S-XXL Model 429R-BK Pro Stabilizer Knee Support