APR Carbon Fibre Front Bumper Brake Ducts (86)Fitment Guide: 86, 12 16 Note: Listing is for front bumper ducts only brake cooling hose and backing plates are not included. Description 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 funnelled 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.