Product review (1 stars): Very poor design.  Broke inside my duct work causing huge repair.  Do not buy!
DO NOT buy this system.  I followed directions exactly and the connectors on the plastic rods broke off during use causing the cleaning brush to get stuck deep inside the duct work.  We had to remove part of the wall to make access panel to gain access to the duct work to remove the stuck part.  Lots of wasted time and unnecessary labor.  I will be demanding a refund and while I'm sure they won't pay for it the manufacturer should have to cover my repair costs.  Cheap junk!