Black Box rack fan tray - 1U is rated 1.0 out of 5 by 1.
Rated 1 out of 5 by robertrost from Fan Tray ReviewThe cost is rather high, but more importantly, you are forced to "load" this fan tray into the front of the enclosure. In my case I have heat in the front, middle and back, so this approach I find is almost worthless. I have since seen modular fan trays that allow you to move the bank of three fans from the front, middle or all the way back, plus add more trays as you cooling requirements increase, which it seems they always do. Just not an overall good design for most applications.