Product review (5 stars): Works Great!
I am replacing a older dryer with a front loader that mounts on a 15" pedestal.  Because of the additional height, I had to move the wall dryer vent up about 15".  In this home, about 10 years old, the vent is a 4" galvenized pipe that runs up an interior wall and vents through the roof, about 17 feet.  In all of my previous homes, the vent was straight out a concrete wall and only about 8" long.  After I cut the duct, I noticed quite a bit of lint in the pipe.  Since I had just purchased this home, I don't know if the accumulation was just "normal" or if the previous owner had just not been consistent in cleaning the dryer lint trap.  It was much easier to clean the vent now rather than pull out the dryer later so I order this cleaning system.  I had to order the extension kit because I needed more than the 12' of rod included.  The quality of this product is excellent and it comes with the best manual I've ever seen for such a simple and inexpensive product.  The manual clearly shows how to use the system in different situations.  The vacuum adapter fits inside the 4" duct and attached to my shop vac. Virtually no dust was observed during the cleaning.  A port in the adapter allows you to run the rod and the brush up the vent, attaching additional 3' rods as needed.  The instructions say to tighen each joint with pliers and then tape them so they won't come apart if you accidently have the drill set to counterclockwise rotation.  I followed the instructions, but unless you are a total klutz with a drill, you probably don't have to do this.  Even so, tighening and taping and undoing took very little time since there are only a few joints.  I had my wife start and stop the vacuum as I connected the rods and worked the brush up and down the duct with the whole process requiring less than 15 minutes.  I opened my shop vacuum when I was done and was surprised at the amount of lint in there.  The manual (and my new dryer manual) caution that if your wall-to-dryer ductwork is either vinyl or thin foil, you should replace it with the semi-rigid flexible metal ductwork readily available at big box hardware store.  I wasn't aware of this before.  The vinyl and perhaps the thin foil ductwork cannot contain a duct fire.  The thin metal ductwork is nice and flexible but the flexibility inherently reduces the diameter of the duct resulting in less air flow and perhaps longer drying cycles.  More importantly, when you look inside you see that the coils are big lint collectors.  I don't know if I will ever use this system again as I am older and probably won't be pulling the dryer out unless I have to.  But if I have to, I will clean the duct while I'm there.  Great to see such a product like this that is easy to use and does what it says.