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. We also want to create a much faster and smoother transition from external to internal setups. 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.