The APR Brake Cooling Ducts are aerodynamically-optimized to "funnel in" massive amounts of air. Also known as the venturi effect, when the vehicle speed increases, this funneled-in air increases in both pressure and velocity as it passes from the larger frontal area into the smaller pipe section of the brake duct. When matched with appropriate High-temperature air duct hoses that connect to tthe rotor backing plates the cooling cycle is completed and large volumes of fresh air help cool down red-hot brake rotors lap after lap on the track. The APR Brake Cooling Kit is a three piece kit that includes Carbon Fiber Brake Ducts, High-temperature Silicone Hoses and Carbon Fiber Rotor Backing Plates.