From manufacture:
Dual Thunderbolt 3 ports and a single USB-C port
Dual, 7200RPM Ultrastar hard drives inside
Daisy chaining for up to 5 additional devices
Ready to go in RAID 0, configurable to RAID 1 (mirroring) or JBOD
Paid $800 for this unit new.
$200 cash and it's yours.