Product review (5 stars): Get rid of that lint stopped-up flex hose
When I saw this device, I knew it was a great idea.  When I pulled out my flex hose, which was installed with a new dryer about two years ago, I could barely see light thought it.  No wonder my dryer kept warning me to clean the vent system!

You've got to do a good job of lining the part that goes on the wall with the dryer exhaust outlet connection, but it's really not that big a deal.  I had to buy a 45 elbow and some straight metal duct to install it, but again not that difficult.  The metal duct cuts easily with kitchen shears and you can seal the joints in the duct with metal duct tape for a very clean, leak free installation.

The dryer is quieter now and I don't expect to see the buildup of lint under and behind the washer and dryer.

Great product!