Sans Digital TowerRAID TR8U 8 Bay SATA to USB 2.0 JBOD/Spanning Enclosure (Silver) Supports eight 3.5-inch SATA hard drives to USB 2.0 interface, using a single USB 2.0 cable. Selectable storage modes: hard drives space could be accessed individually (JBOD) or could be combined into larger volumes (spanning). 3 spanning modes available: single spanning set with 8 hard drives, two spanning sets with 4hard drives, and four spanning sets with 2 hard drives. 2 selectable power modes: Normal Power Mode (manual ON/OFF), and Auto Power Mode(synchronized ON/OFF with the connected computer). USB high-speed (480 Mbps), and backward-compatibles to full-speed (12 Mbps) data transfer.