Made from heat treated spring steel, they are hard, smooth and resilient, and function like a skid plate on a real off road race truck. They slide up and over obstacles bouncing off frontal impacts without permanently bending. They simply work better than any aluminum or titanium skid plate. They also eliminate the need for bumpers on the T/E-Maxx. We don't use bumpers on our Traxxas trucks. Bumpers can bend or break, and can break your bulkheads. So our skid plates were developed together with the roll cages to eliminate conventional bumpers. Our skid plates are .042" thick, (the same weight as 1/8" aluminum and .060" titanium), and are bright zinc plated.