RTII235DCSH RAID Tower II (black color) with 1 2X1 eSATA/USB 2.0 Hardware Port Multiplier installed. Install up to two 3.5" SATA hard drives of any capacity. Drives are installed onto drive enclosures that can be added or removed like tape cartridge from each drive bay. Connect to system via USB 2.0 or eSATA port (connecting cables included). Drives can be configured as FAST (RAID0 Striping), SAFE (RAID1 Mirroring), JBOD* (Just a Bunch Of Disks or individual drive), BIG (combined single volume), SAFE50, SAFE33. RAID setting via a rotary switch on the back. OS independent, can be used on any system.