RPM engineers reviewed the stock bumper mounts and found that there were several areas that could be improved. Both the front and rear RPM bumper mounts were widened (the front more so than the rear) to allow the bumper mount material more flexing room. We also curved the center connecting rib to allow the bulkhead mounting points the ability to rotate at the mounting screws, allowing more impact absorption and less energy transference. Our last major design improvement is the one everyone is most familiar with RPM Black Front Bumper Mountcustom-blended nylon! Our material is the toughest stuff out there with just the perfect blend of rigidity, flexibility, durability and memory.When quality counts and protection is needed most, RPM is the company to turn to for the ultimate in American designed and American made aftermarket R/C products!