Product review (4 stars): Works well if your vents are "just right"
It's nice and works well. We bought this specifically for the additional segments.  Which worked out well until the the came off. All of the segments were taped together (as recommended on the kit) but the head doesn't have that capability. For whatever reason (maybe my wife got the drill running in the wrong direction) the head came off.  We were able to attache (tape) a short length of coat hanger and pull it down.

Please note, also, that the segments are kind of flexy, but will bend if pushed too hard. You will need to only attach a segment as you run out of room. We also used a large box end wrench to hold the rod.  This prevents it from flexing and whipping.  Which may have bee the reason we lost the hear. We bent one segment.

Due to a crap design in the house we weren't able to clear the whole vent and the system got stuck, terminally. Turns out the builder made a design flaw and the vent pipe made a 90 degree bend before angling to the roof.  This system isn't intended to do that. The guy who came out to retrieve our head and rods and finish the cleaning had a "better" system.  For about three times the price.

This system would probably have worked better were it not for that little design flaw in the house.  However we also had a 10 foot rise to get into the the attic and then another 20-25 feet to the jack. So in addition to our 8 foot original kit and this 12 foot kit we would have needed another 2 12 foot kits.  Ouch. Assuming the bend wasn't there.