Our FS-15 Series Rock Sliders for the 2021+ Ford Bronco were designed to protect the sides of your ride from large rocks and other obstacles on the trail. They serve as a more robust replacement for the available factory steel rail.?They mount directly to the frame using factory hardware, providing maximum rigidity and preventing damage or bending to the steel side body panels. The tubes are constructed from 3mm steel & the plates are made from 5mm steel, providing superior protection. They come finished in our Micro-Texture Black Powder Coat to match factory trim and prevent rust.