Reducers and Ports are all polished lightweight spun aluminum that is corrosion resistant and can withstand high temperatures. The design allows for transitions between 3 inch and 1.5 inch. Installation is easy, using our FAST Fittings, and duct tape or duct clamps to connect the duct adapter. Air entrance ports are used as NACA ducts for hose feeds, and are also used by racers for body panel sleeves.