The Turner Motorsport carbon brake backing plates are made of pure carbon and high temperature resin. Our unique design specifically for the E46 and Z4 (not M) is optimized for 3" hose and allows the air to flow directly to the rotor with no impedance or obstruction, and with a considerably lower weight than competing products. When flow tested compared to a competitor’s product, the Turner brake ducts flowed twice as much! This greatly reduces the chance of brake fade, boiling the brake fluid, and wear and tear on your brake components. Installation is easy, as it does not require removal of the wheel bearing, by making the backing plate in two parts. The main backing plate and a block off plate that bolts together. Most companies just have a big slot so you can slide the backing plate on, but then it just lets air flow right out the back end. Since we seal off the entire center hub of the rotor, we can maximize cooling airflow to the center of the rotor.