Rated 2 out of 5 by 1
Rated 2 out of 5 by CanoeJon Stupid Construction
In terms of the airflow, the opening is significantly less than 5 and 7/8". Spot welding should have been on flaps that folded to the outside of the duct collar so as not to constrict the opening. I brought it to a shop and basically rebuilt it.
February 6, 2009