Perrin PSP-INT-430RD Red Intake Inlet Hose Pipe for 2013-15 Scion FR-S / Subaru BRZ Smoothest air path for ZN6 : Adds color to the engine bay : 3 Inch diameter The PERRIN inlet hose is perfectly smooth on the inside and has a larger radius bend toward the throttle body. The support adds rigidity to the hose and prevents collapse when used with restrictive filter elements and high horsepower cars running higher redlines and big cams. The PERRIN inlet hose will let you maximize all your performance power upgrades. DIAMETER FOR MORE FLOW The PERRIN - inlet hose has a 3" internal diameter compared to 2.7" found in the OEM part.