LaCie 4 TB 2big Thunderbolt Series 2-Bay RAID Hard Drive (9000191) Box Content - LaCie 2big Thunderbolt Series, Drive stand for upright use, External power supply, CD with User Manual and software (Intego Backup Manager Pro), Quick Install GuideFeatures Shocking speeds up to 327MB/s RAID 0/1 flexibility - speed or security with Mac OS Dual Thunderbolt ports for daisy chaining Two hot-swappable disks for non-stop data access