When you drop down the black air duct, you are able to reveal the hard drive cage that is completely covered by the large air duct. This is so that the hard drives that you may have installed are able to receive fresh air to be cooled with. When you take a closer look at the hard drive cage, you can see that directly in front of it a fan measuring in at 120mm size and colored bright yellow like the other fans. There is a tab that you are able to lift up that will allow you to rotate the cage a little so that you are able to remove the 120mm front air intake fan, as well as allow for a more convenient way to run any wires you need to hide.