Articulated Knee Armor High-impact nylon; super tough, black removable wing, new styles avail. soon; fits med - large three up three down articulation, over 180 degrees flexion with no gaping; solid brass Chicago screws with rosette heads; great side and impact protection, remove wing for stealth. Our articulated knees, like all our products, aren't simply put together - they're designed. Sixteen different materials were tested, and we found the high-impact nylon used in these to offer the best combination of stiffness and durability. The original prototype was made by a master armorer and translated into the design we have here after several tweaks to better be produced in the injection-molding process - the initial investment in these molds ran into thousands of dollars, and needless to say, every effort was made to make an all-purpose design with the widest range of use and aesthetics possible. The sets are designed with medium-to-large circumference knees in mind, allowing between 1/4" and 1/2" of thickness for knee pads; flexion is well over 180 degrees with no gaping if unmodified. Black only