Product review (5 stars): If you own a dryer, you NEED this !
Yes, You need this whether you think you do or not.  The inside wall of your vent is damp, catching all the stuff your lint filter can't.  I was appalled at what came out  -  It opened my eyes to what a tremendous hazard is lurking well out of view.  I now have reminders in my phone to perform this 3 or 4 times a year.
* This set was simple, straightforward & easy to use.
Be prepared with a cordless drill, 2 pairs of pliers, & duct tape.  Some reviewers complained about the need for tape, but personally I didn't mind. Yes, I'm certain they could utilize a screw system like the one which attaches the brush, but do you really want to fiddle with a little tiny screw & Allen wrench every time you add or remove the next section of rod?  It's much simpler to use pliers to snug the rods & wrap with a short little strip of tape. (I had half strips of 2-1/2" tape ready to wrap as I went). The tape is cheap insurance in case you hit the reverse on the drill, potentially causing the rods to come apart deep inside your vent.