The optimum combination of mega storage capacity 1 TB (500GB mirrored) preconfigured in RAID 1. This powerful RAID subsystem comes in a 2-bay array with swappable hard disks and built in RAID controller. It can be plugged in using your USB port. The system is pre-configured in RAID 1 and offers automatic background rebuilding for optimum security of your files. The mirrored set will automatically rebuild itself if one drive fails. Ideal for saving and protecting files, video, music and photographs. It delivers high-capacity performance and redundant data security.