The ExpressCage MB322SP-B is a mobile rack that converts a 5.25" device bay to fit two 2.5" SATA/SAS HDD/SSD, and includes a 3.5" slot for either a hard drive or a 3.5" device. With the unique tool-less drive installation design, the ExpressTray mini allows you to install your 2.5" SATA or SAS HDD/SSD simpler than ever, and the optional bottom tray screw holes are provided for added stability. The MB322SP-B has a detachable dust cover which keeps the front panel enclosed to block out dust particles when the 3.5" slot is left unused or when there's a 3.5" HDD installed. Soft blue LED indicator lights on each 2.5" drive bay notify you when drives are being used without being too distracting.