The floppy disk was once the king of the 3.5" drive bay. It was standard procedure when you were building a new computer to get a 3.5" floppy disk drive. This reign lasted for over a decade until CD-ROM drives started taking over. Now, we are getting to the point were everything is moving into the the realm of USB and eSATA, so 3.5" drive bays are going neglected and unused. Standard procedure has changed, so companies are coming up with innovative ways to use the empty drive bays.
The iStarUSA miniDUAL 2.5" HDD/SSD to 3.5" Internal Drive Bay Cage looks to help make use of that unused drive bay. The iStarUSA miniDUAL Internal Drive Bay Cage allows you to expand your computer further by adding an extra two 2.5" hard drives that can be hot swapped. The miniDUAL has a sturdy aluminum construction and allows use of a hex key in order to lock the drives securely into the bays.
Here is a little information about iStarUSA taken from their website. "iStarUSA, Inc., established in 1989, is a Taiwan-based company with over 20 years of experience specializing in OEM/ODM projects and manufactures industrial Power Supply, DVR/IPC rack mount chassis, and Rack mount cabinet. Having the belief of "Always provide our customers with the best products and superior customer services," iStarUSA has grown to be one of major provider in IPC power supply Industry."