Product review (2 stars): correct packaging, wrong item
the metal does seem sturdy and thick.  however, we ordered the 18-9 inch unit but received the 0-18 inch unit.  the markings on the package insert state 18-29 inches.  however, when we slid the vent, the outlets moved closer together, not further apart.  the instructions showed pictures of all the diff whirlpool vents, and ours was exactly like the 0-18inch.  We had to return it.  We do not want to exchange it for fear they packaged more like this and i do not want an incorrect item twice.  Further, the metal was bent around the base of one of the outlets creating a hole where air would escape into the room.  If we had the correct part, we could have bent the metal and worked the outlet back into place.  It would have taken some work and possibly a cut or two but metal is metal and can be worked with.

I'll give it 2 stars because it does slide solidly and is decent quality.  Too bad it was damaged and the wrong part.