Product review (2 stars): High Maintenance & Poor Quality = Mo' Problems
This product has multiple flaws.  I know, because I have owned several and am now systematically replacing them.

1)  The vent sticks out too far.  In one of our installations, it often gets bumped into and we have to periodically fix the damaged mounting points.

2)  The device needs regular cleaning.  All vents need cleaning, but this design makes this a more frequent issue.  The "pop up" vent also allows lint to fall back into the vent tube, which usually cakes in layers, which impedes airflow over time.

3)  The plastic hardens over time and becomes very fragile.  You will have to replace the top often.  Of course the manufacturer sells this piece at an inflated price, with a pricey "handling" charge.  So basically they gouge their loyal clients.

I have gone from loving this product to hating it (along with the manufacturer).  You can do better than this!