Braces from leading brand POD. Improved lightweight composite frames are anchored to hinges for optimal load transfer from the knee joint. HUMAN MOTION New Hinge The intensity of modern sports puts the human knee at significant risk, so they developed their own synthetic straps to reduce the stress on your knee. Inspired by the human body, POD's patented Human Motion technology uses the power of synthetic straps crafted from Vectran Fibers (5 times stronger than steel) to provide advanced multi-directional motion control. Enhanced Protection: CE-tested full coverage mechanisms protect against impact, as well as enhance comfort when kneeling. The impact shield can be easily removed to convert the brace for use in other sports. Medical Compliance: The knee is one of the largest and most complex joints in the body, with large bones held together by four ligaments that are essential for joint stability and proper function. The K4 Knee Brace has been certified as a medical device to help prevent leg and knee injuries such as ACL, MCL, PCL, LCL, rotational and combined instability. Measurements: Knee circumference should be measured directly below the kneecap using a soft tape measure or string. Take measurements in a fully extended weight-bearing position (i.e. with the leg fully straight). X-Small / Small 11.6" - 13.4" M\L 13.4" - 14.8 X-Large / XX-Large 14.8" - 16.8"