Lower air duct without insulation, 9/67>
Cardboard air duct without foam insulation lining. Goes in front wing and connects to front bumper air intake. Fits all 3rd front models (9/67>), 2 required per car.
We find that the insulated version of these ducts have a much restricted air flow and this is more detrimental than the benefit of the insulation, so best to use the non-insulated lower duct in conjunction with the insulated larger diameter upper duct.