This is the same vacuum line assembly that we ship in our fuel kits including the 7th injector kit for the 5VZ 3.4L applications.
This restrictor T assembly is used in our fuel kit and 7th injector kit for the TRD/Magnuson supercharger using the older 3 lobe MP-62 rotor assembly. This prevents impeller noise/pulses from traveling through the vacuum line to the Performance Calibration Unit and makes the MAP sensor BUZZ.
This is not needed for the newer Magnuson supercharger using the TVS-1320 rotor pack. Just a simple vacuum line assembly will work fine.