FACTORY DIRECT ONLY: Slim ODD x 1, External 5.25" x 4 or Hot-Swap 3.5" x 6 or 2.5" x 6, Internal 3.5" x 1 or 2.5" x 1, USB2.0 x 2, PCI slot x 7, Power Status, HDD, LAN Activity LEDs. OPTION: 500w single or 500w redundant