External docking stations are popular because of its flexibility and compatibility. However, because it is for external use, the interface limits the transfer speed of your hard drive while only allowing one to be use at a time. In a standard computer case, there are several 5.25" bays usually reserved for your DVD ROM drive, however, will not naturally fit with your 2.5" or 3.5" hard drives without some assistance. Using the MB971SP-B DuoSwap, you will save precious desktop space by integrating both 3.5" & 2.5" slots into a single 5.25" bay. This gives you the ability to expand and easily go from your external docking station to your computer in just seconds. Some key features that help make using the device simple to use are: Individual LED's, power button & eject button. Because the hard drives are connected internally, you will be able to transfer your files up to SATA 6Gb speed. You will be able to finish the job done much faster than ever before with this setup. The security of your hard drive or SSD is a non-issue as the "Eagle-Hook" mechanism switches on immediately after the 3.5" drive is inserted and locks the 3.5" hard drive in place. Having an easy way to use your hard drives as they should be used, without the worry of installing or removing makes it a must have accessory for any personal PC, Lab testing PC or HDD duplication system.