Product review (5 stars): Works exactly as advertised
I cleaned a ten foot long hard vent line with a 90 degree turn at the end by attaching one extension at a time.  This tool left the vent cleaner than its ever been and had no problem making the turn. I attached my shop-vac to the end of the line and it made for a nice mess-free job.  If you have a problem with this tool it's because you didn't read the instructions.