SilverStone Technology RL-FS304B Front Bay Hot-Swapable Hard Drive Enclosure Fits four 3.5 SAS/SATA 6Gbit/s drives in three 5.25 device bay Adjustable drive status LED and fan control system Trayless & screwless design Individual metal key lock for each drive for extra security Individual metal key lock for each drive for extra security Independent drive status LED Built-in cooling fan for excellent heat dissipation Fully supports SATA Hot-Swap function