Product review (5 stars): It works!
My existing gas dryer in house that I purchased didn't generate enough hot air to dry clothes.. I thought gas dryer had a problem, then purchased new dryer (big mistake!!!!). When I tried new dryer, it had same issue. I checked the Amazon and Googled it, then found this vent cleaning system. I purchased it with extension set since my unit's vent is 2 story high to give a try.. Worst case, call other cleaning company. OMG it works great! First it still caused same problem since I initially used 4" brush.. It was a little mistake. I think it pushed lint up, so it just clogged even worse.

Try 2.5" tool and blockage removal tool first, then use 4" brush to clean up any remaining small lint around pipe.

I could save new dryer cost if I tried to clean the vent with this tool first. Highly recommended.