This BUSlink 4-Bay RAID hard drive supports large capacity and dual USB 3.0+eSATA interface. It supports Intelligent RAID function: RAID 0, RAID 3, RAID 5, RAID 10, and Large. Removable HDD trays support hot-plug replacement of drives (only for RAID with redundancy mode). HDD intelligent sleep function is supported. The LCM display and buttons support convenient setting of RAID modes and status display. Optional password allows locking of RAID settings. Cooling fan maintain safe operating temperature. Included CD allows software control of RAID mode and status display in PC. Skid proof and shockproof rubber feet mat ensure safe operation. BUSlink CipherShield encrypted hard drive prevents unauthorized access to your digital data. Using the latest cryptography algorithm software to protect sensitive file is nothing new. However, loading that same encryption into a removable CipherKey - that when removed not only makes all the data stored completely unreadable, but the drive itself becomes transparent and is completely invisible to the operating system. Plug the CipherKey in, the drive is once again visible and files immediately decrypted and accessible. Now that's new. The fact that this drive can plug into any USB port and is immediately accessible on any operating system, is just icing on the cake.