Reply from Forest River:
The MaxAir fan that we install is made to be able to snap a compatible cover over the vent. Forest River does not sell this product. You should be able to purchase said cover at a dealership. If I can be of any further assistance, please do not hesitate to reach out.
Installed the MaxAir Fan Mate cover today. Very easy install with NO drilling required. Mounting post preinstalled. Just slip the attachment pins to the post.