Norco 4U Rack Mount 24 x Hot-Swappable SATA/SAS 6G Drive Bays Server Rack mount RPC-4224 4U rack mount design 24x hot-swappable SATA/SAS 6G drive bays Six internal SFF-8087 Mini SAS connectors support up to twenty-four 3.5" or 2.5" SATA (II or III) or SAS hard drives Backplanes are horizontal mounted for better ventilation LED indicators for power and activity on each HDD tray Support EEB (12"x13"), CEB(12"x10.5"), ATX (12"x9.6"), Micro ATX (9.6" x 9.6"), Mini-ITX (6.7" x 6.7") motherboard Redundant 4pin Molex PSU connectors support redundant power supply Two front USB ports