HI : I have to drive at least 20 miles on gravel each day , super fine dust would coat the rear bed of the truck ( I do have a cover installed ) , tried sealing the end gate , better but still the dust would enter . So I added this to the truck , no more dust at all in the rear bed . ( It looks ok I think , and it does the job ) . used some 4 inch PVC , and a 4 inch TA (terminal adapter) . And yes , I can open the cover right up after the adjustment . Just some positive air pressure is all you need to keep the dust out .