Sans Digital MobileSTOR MS4CT+ 4 Bay USB 3.0/eSATA/1394a/1394b Hardware RAID Enclosure 4 bay Hardware RAID enclosure with hot-swappable slots and dust-free cover. Auto / manual adjustable cooling fan speed to enclosure quiet and efficient cooling. Hardware RAID embedded to the enclosure to eliminate OS compatibility issues. Trayless design and dust-proof front cover. Hot-swap supported. Auto-detected newly inserted hard drive with auto rebuild. Quad Host Interfaces: USB 3.0 (backward compatible with USB 2.0), eSATA, Firewire 400 and Firewire 800. Easy to read display panel for RAID and system status. Features five different RAID modes, including RAID 0, 1, 1+0, 3 and 5 for redundancy, performance and protections. Also support spanning for simple storage expansion.