Question about Icy Box Cloning and docking station for 2.5" or 3.5" SATA drives,IB-1232CL-U3

When I plug in my 3.5" hard drive, I can hear it start to spin. But after about 5 seconds it stops spinning again. I can't see it on my MacBook Air. Am I doing something wrong or is the device defective? I took it out of the original packaging 5 minutes ago. I have also tried it with two other 3.5" hard drives.