Product review (2 stars): Poorly made.
Purchased this unit because it was made in USA, big mistake. Parts were missing, the cutout for the duct was stamped so lightly that it had to be cut out which caused the top to deform. The damper frame is so flimsy when you fasten it it twist, only had screw holes on one side. I got it installed the damper rattles like crazy.  The cover for the wiring did not fit until I twisted and bent it.  It looks nice, I like the variable speed fan but its not well made.  The filter has to be bent just to install it.  I would not recommend.  Oh ya the black cover for the vent if using ventless looks awful.  Should have had some type of design over it if the venting option is used, not just a black strip.  Would have given it no stars but I do like the variable speed fan.  But don' t buy it for that reason.  I had to get it installed or it would have been sent back.  Did I mention don't buy it.