Product review (4 stars): Good quality for the price, but could be better
The local hardware stores only had vents for installing in a wood wall or on top of siding, I needed a kit to install through a brick and block crawlspace wall. This kit allowed me to do just that.

The flaps move freely after a 20' run, yet not so freely that exterior wind opens them. Everything (other than drilling the hole through 1' of brick, concrete, and cinder block) installed fairly easy.

The two reasons I am deducting a star are that the item came stained. I plan on trying the Mr. Clean Magic Eraser on it to get the stain out and if that doesn't work I'll just have to paint it. Also the mounting options are to drill screws into the mounting surface or to silicone it to the wall. Since it doesn't come with screws I assume the ideal mount is silicone, so I believe there should be some caps to cover the screw holes. It's nothing major, but a little touch like that would have elevated the product enough for me to ignore the staining.