3U (Rackmount), 4 x 6 Gb/s SAS Host Channel, 4 x 1Gbe iSCSI Channel, 16 x 3.5" 6Gb/S SAS/ 3Gb/S SATA Disk Tray (Bay), 2 x Controller w/ Cache (1GB Default, Upgradeable w/ 2GB, 4GB), 2 x Cooling Fan (Fault-Tolerant), 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, &