Instead of blowing air aimlessly around the wheel well, these brake ducts finish where GM left off. Air is blown directly into the hub/rotor area to dramatically reduce rotor temperature. Works with up to 10″ wide 18″ tall front rims. These are now standard equipment on our C600/RSR. We recommend using these in combination with our Stainless Steel Braided Brake Lines and Stainless Steel Pistons for the ultimate in repetitive and high speed stopping performance with stock GM calipers Kit includes left and right ducts with high temp hose and clamp. All hardware included with instructions. 2 hour installation time. A must have for any modified braking system.