If you are asking about fantastic fan vent covers, then we really like our Maxxair II vent cover. Easy to clean due to the hinge on one side. We keep our vent open year round, rain or shine, and it keeps the rain out.
I don't have any experience with the replacement fans though.
John-Dave and Marilyn
04 Dodge Dakota V-8, 17 Dodge Durango V-6, 19 Ford Ranger 2.3 Ecoboost