Product review (5 stars): Bye bye birdie!
Worked better than expected.  Did eventually get the extension pack to help clear a 24' run of dryer vent.  Birds weren't too happy.  Shocked the previous owners didn't start a fire with as much debris that I cleaned out.

Extremely easy to use and quick to master.  Used this from inside the home rather than climb extension ladder to the exhaust vent near the roof.  Laundry is on the 2nd floor.  Shop-vac attachment worked well.