Product review (5 stars): Works great!!!
I read a ton of reviews before I bought this and I'm simply amazed and very happy with this purchase.

The product works as described and I think the problems that people were having are due to their lack of READING the directions.  If you read the directions and do exactly as you're instructed, you will have ZERO problems with this product.

I have about 12' of 4" metal ducting in my home and this product cleaned it out with no problems.  I finished the entire project in about 20 minutes.  It's very easy and really hard to screw up.

My only advice is to tape a plastic bag to the dryer vent hole to catch all the lint as you take the cleaning brush out.  I didn't do that and ended up with a massive pile of lint in my bushes.