DS-540N 4-bay eSATA/USB 2.0 Storage Array with Hardware RAID 5 Support High Speed eSATA and USB 2.0 interface Supports greater than 2 Terabyte RAID drive and hot-spare Supports RAID levels 0 / 1 / 3 / 5 / 10 / JBOD / CLONE 4-bay 8TB + massive storage capacity support Supports on-line Auto-Rebuild at 200GB/hour