Product review (4 stars): man am I glad I got over there and had this tool
I own several rental houses and each one has different lengths of vent runs.  I had a call from my tenant who told me that the clothes were taking a long time to dry so I knew that the vent was probably plugged up.  I saw this kit on amazon and decided to try it.  Upon receiving it, I wasn't that impressed, the brush didn't seem very heavy duty and the six threaded fiberglass rods with metal tips seemed rather cheap.  Well, only one way to find out, I took it over to rental and assembled a couple of the rods, using my cordless drill for power.  It was raining lint, man am I glad I got over there and had this tool, it cleaned the vent out using all six rods.  It worked great, problem solved, I was able to clean out the vent going in one direction.  The tool worked so well I used it on two more houses with no problems and great success.  It may not look like much but if you realize it's only a homeowners version, not industrial strength, using it as such, it's worth doing it yourself with this kit.