The Joint Knee places the VPD material around the front and sides of the kneecap, right where you'll need it. Stretchy, perforated neoprene covers the back of the knee joint. It's perforated to add some breathability for sultry summer afternoons at the bike park. The rest of the Joint Knee is finished with an aramid cloth making it remarkably abrasion resistant. And to keep it snug and in-place right where you want it, there are elasticized velcro straps at the top and bottom. The Joint Pads are also slim enough to wear under jeans or shorts without leaving you feeling restricted.