Skunk2's 84mm - 90mm Big-Bore Throttle Body Cold-Air Intake Coupler allows for easy installation of Skunk2's '06-'11 Civic Si Cold-Air Intake when using a Pro Series Throttle Body or similar (also compatible with OEM TL throttle body). Simply replace the Cold-Air Intake system's included silicone coupler with Skunk2's 84mm - 90mm version for a simple, factory-like fit. This item fits .