Tunnel and it reduced sound and heat especially on my right leg and I really can't believe how much it helped with the heat. I will locate the Mfg and additional photos tomorrow. As far as the spare tire fitting withe the additional material, it fits fine. HTed to get rid of my spare but since it didn't have a purpose it is gone lol. I also elected to remove the jack and lug wrench as well. That area now holds a small tool pouch. I think I have some additional pictures I can share of the progress as I did several modifications while I had it down including additional stero amplifiers, stereo rewriting, Walbro 485 fuel pump install, optima red top battery, ets