RPM Nerf Bars Slash and Slash 4x4, BlueRPM has once again stepped up to make the most durable and well designed nerf bar for the Traxxas Slash 2wd and Slash 4x4. The RPM nerf bar eliminates the stock hook over the chassis that supports the nerf bar and replaced it with a structural cross rib running parallel to the chassis for optimum rigidity and anti deformation characteristics. By eliminating the hook, installation is easier; the nerf bar doesn't have to be deformed to get it in