Product review (5 stars): My dryer is super silent now, no rumble/knock!
Holy hell! Let me start by saying Thanks to YouTube for including very simple instructions to replace these parts.

Now that we have that done, let's get to these parts. Dryer was simple to remove the bin/hopper thing and left a huge area to work with. The old rollers were so worn down, one of them had only a small chunk of rubber on it. The tension piece was bent and wasn't giving much pull to the belt. Replaced all the parts in about 15 minutes tops (would have been faster but my cat wanted to help). When I put the bin/hopper back in, it was VERY TIGHT! I had to make sure everything inside was lined up perfectly, reassembled everything and turned that bad boy on. It was like God sent down a special angel to sing me a silent song of a working dryer again! It was SILENT!!!!

These parts are cheap enough that I may end up picking up another kit, just to change it yearly, or more often, as this is something that is simple to do, and very easy to prevent issues down the road.

One other amazing thing about needing to change these parts, I was able to vacuum out the inside area of the dryer. There was so much lint in there, that I was thinking "FIRE HAZARD!" Remember to clean everything and make sure it's unplugged before starting!!