Sans Digital MobileNAS MN4L+ Linux NAS + iSCSI 4 Bay Storage Tower (Silver) 4-bay NAS utilizing Intel Pentium M CPU and 512 II DDR memory for ultimate performance. Built-in account management allows safe data keeping by giving read-only or full read/write to specific per mission to users or group. One eSATA, two USB 2.0 & one Firewire 400 external hard drive expansion ports. Built-in snapshot, NAS-to-NAS folder replication, iSCSI initiator and target support. Utilizing the latest SATA II technology the MN4L+ supports hot-swap with RAID I (mirroring), RAID 0 (stripping), and RAID RAID 1+0, RAID 5, and RAID 6 allowing the protection against hard drive failures or expanding usable drive space.