The internal fans are UNUSUALLY valuable when extended transfer times are involved (hours/days)

Each cooling fan has an adjustment control on the back of the unit to adjust the speed of the fan or turn it off completely

There are 2 cooling fans in this dock

This unit automatically turns off both cooling fans when all drives are turned off

If I only have drives in the left side of the unit, it would be nice if only the left cooling fan turned on and vice-versa.

It works just as it supposed to

Worked exactly as I expected, with no problems