Product review (5 stars): Excellent Product
This dryer fan was easy to install, and unlike other dryer fans, is able to be installed directly behind the dryer.  Most fans require 15 feet of vent to avoid clogging the motor, but this fan is located out of the airstream.  This was perfect for my installation.  My dryer vent runs under the slab, so I am not able to install a fan in the attic.  This made a big difference in our drying time, and i'm sure it will reduce maintenance on cleaning out the vent under the slab.  Only 2 things I would change - 1.) add a light to be able to see if the motor is running.  2.) the locations of the vents are awkward. If the unit is to sit behind a dryer, it should be easier to lay it horizontally. As it is, it is easy enough to lay it down, you just have to detach the sensor so that it remains vertical.