Mediasonic HFR2-SU3S2 Pro Raid Box is a 4 Bay Enclosure. The main feature of Pro Raid Box is its Hardware Embedded Raid function. It supports RAID 0/1/3/5/10. Support 3.5\" SATA I/II/III hard disk drive up to 6TB per drive, Hardware Raid controller built-in on board, Transfer rate up to 5.0Gbps via USB 3.0, Transfer rate up to 6.0Gbps via eSATA, Power Sync: Power off in synchronization with PC, One button for RAID control,Forced Convection Process, Smart Fan function.