The economy of space inside a case might be limited for users who are looking to build a server. Most mid-tower cases have space for at least three or four 3.5 drives but when those are fully populated, there are solutions available that can take advantage of the often unused 5.25-inch external drive bays. Most of the products available in the market essentially just convert two available drive bays into three usable mounting storage for 3.5-inch drives or four bays into three drives, so users looking for a more flexible solution with plenty of extra features and convenient mounting will probably have to look harder.
Thankfully, Icy Dock has the MB973SP-B and the MB974SP-B SATA backplane cages. The FlexCage MB97 series backplane cages feature tray-less mounting for 3.5” drives and offer full SATA 6 Gbps speeds. An additional USB 2.0 and eSATA connector is located on the front panel of the FlexCage modules as well as fan control options for the rear 80mm fan. The FlexCage MB973SP-B and MB974SP-B have front indicator LEDs for drive functionality and utilize a multi-lock design to prevent accidental ejection from the hot-swap bays.