Professional Awesome High Downforce Splitter Diffusers: Designed and optimized using CFD to ensure the best possible performance. Once installed, diffusers create a low-pressure transition zone that greatly increase the downforce potential of any splitter. Designed to be installed on an otherwise flat splitter, instantly turning it into a high-end, active front element for a fraction of the price. Use in conjunction with our universal vents to maximize downforce gains. Engineered and manufactured in the U.S.A. Made from high quality, durable ABS plastic. 2 diffusers, left and right, included per purchase. Diffusers are 2.25″ tall on the short side and 4.5″ for the tall side. Used on the record-breaking Professional Awesome Time Attack Evo. Install tips: Ensure adequate room in front of and behind diffusers to ensure airflow isn’t constricted for maximum performance. Designed to be riveted, bolted, and/or bonded to a splitter. Please ensure your splitter is properly attached to the car. These can, and will, create much more downforce and can rip the splitter from its mounts. YOU’VE BEEN WARNED!