Abstract: A removable wind deflector is provided for a freight container which may be shipped on an open or flat bed truck, railway car, etc. This reduces the need for an expensive air flow cowling on the truck, and reduces the load on the gear and brake systems, besides improving fuel consumption. The assembly of the deflector and the freight container also permits the user to reduce capital costs inherent in a permanent trailer and box combination. The wind deflector may be attached and removed quickly, without extensive labor, and without changing the shape of the container.