Decrease lift and drag dramatically on your WRX/STI with a simple bolt on diffuser. By using CFD to aid in the design stage, we were able to extract more performance out of our initial design as well as prove the unit will function in the real world. Construction: 0.063 Thick 5052 Aluminum Stainless hardware throughout Features: Powder Coated Matte Black Organic Shape Flat head riveted strakes (No rivet heads visible, flat bottom) Simple Bolt on installation Reduces drag Significantly reduces lift Optional 2pc differential/suspension covers reduce drag even further and aid in feeding the diffuser clean air. Confirmed Exhaust Fitment: Stock Exhaust Agency Power Exhaust Blitz Nur Spec Blitz Nur Spec F-TI Borla Exhaust Cobb Exhaust Corsa Exhaust ETS Exhaust Sysemts Greddy Supreme SP HKS Hi-Power (all) HKS Legamax HKS Super Turbo Injen Invidia N1 dual Invidia Q300 single and dual Magnaflow Exhaust Milltek Exhaust System Mishimoto Nameless axle and cat backs Perrin RCE Clubsport SubiSpeed  Turbo XS X Force Confirmed Exhaust that Needs Trimming: Invidia N1 Single Tomei Type 80 STI Upgraded Exhaust - Dealer Option Model Installation Manual Informative Packet