vent covers for heating grille

[dberg]

Iam looking for a round cover for the heating supply grille on the heating system to the garage area of the trailer so that supply of air will go out of the front bed room vent stronger better yet if they could be replaced with one that are adjustable to close or open them as needed
if you know of this kind of product please let us know

[Eagle]

Don't recall seeing a grill cover that would open and close.

Seems like it would be easy enough to pop the grill cover off, stuff some insulation in the vent tube and put the cover back on.