Composed of 100 percent latex-free 4.8 millimeter neoprene (CR) with exclusive binding, straps and cover fabric. Available in sizes small, medium, large, extra large and double extra large. To find your correct size measure the knee to be protected (you likely figured that). Stand and bend your leg just less than 45 degrees, measure around the largest part of knee, directly over the patella (kneecap).