2U (Rackmount), 4 x 6Gb/s SAS Host Channel, 12 x SAS/SATA Disk Tray (Bay), 2 x Controller w/ Cache (1GB Default, Upgradeable w/ 2GB), 2 x Cooling Fan (Redundant), 2 x 530W PSU (Redundant), 2 x BBU (Battery Backup Unit), 2 x SAS Expansion Channel, Options-(Advanced Data Service license, Flash Backup Module, Mux Board, Hard Disks, Spare FRUs, & Other Accessories)