Product review (5 stars): If you have a dryer, YOU NEED THIS.
Great product!  Worked as advertised.  This can be a life saver, I mean literally.  Lint can easily caught on fire in your duct especially if your dryer is old and doesn't warn you when the vent needs checking.  If you follow the instructions you should be OK.  The vacuum adapter is great and works as designed.  I would advise any one with no experience with power tools to take a couple of minutes to get familiar with the whole set up.  The only improvement that I see could make it better is instead of the round cylindrical surface on the metal connectors, what about an hexagonal surface that would be so much better for tightening with a wrench or pliers and the last connector would fit much better in the drill chuck; even just two parallel flat surfaces would have been better.  But apart from this minor convenience, everything works like a charm.