4.5 of pure carbon power. Presenting the S - FLO Carbon Inlet Tube for the Audi 8V RS3 and Mk3 TT RS The S - FLO Carbon Inlet Tube is the largest amongst its peers, with impressive adaptability to facilitate maximum gains. The colossal 4.5 S - FLO Carbon Inlet tube bridges the gap between the turbo inlet pipe and the factory airbox seamlessly. The S - FLO Carbon Inlet Tube is for drivers looking to extract the most out of their factory airbox while increasing throttle response. Upgrade path The S - FLO Carbon Intake Suite is modular by design allowing an easy evolution from the S - FLO Inlet Tube or S - FLO Shortie Carbon Intake to the full S - FLO Carbon Intake Systems (open or closed). S - FLO 4 Coupler The S - FLO Carbon Inlet Tube come complete with a 4.5 to 3 couplers to mate to the factory 3 turbo inlet pipe. The S - FLO 4 Coupler transitions from 4.5 to 4 to accommodate aftermarket turbo inlet pipes that are 4 in diameter and is available separately (SKU 7260 - 11002).