Product review (3 stars): Great idea, but quality is poor
I purchased two of the Lambro 289W Dryer Vents.  I like the idea and it should work well except that the plastic cylindrical cap inside that slides up and down to seal the air is deformed and sticks so the seal  doesn't close.  I've emailed Lambro for a replacement seal - we'll see how they respond.  I wonder if the Heartland 21000 is better or the same - they sure look the same.