The Dewhot units are for outside use. However if they are mounted where the rain or strong wind can get to them then you need a cover.
These covers also offer added security against theft.
They are made of galvanised steel.
They have a slanting top to shed off rain. No flue required.
They have keyhole mounting slots so that they can be removed if required.
They come with the necessary screws for easy assembly and mounting.
They allow for temperature and gas adjustment when fitted.
They can be painted the same colour as the wall to blend in.