Akitio Thunder2 Duo Pro Thunderbolt 2 for lighting fast transfer speeds up to 20Gbps Dual interfaces featuring Thunderbolt and USB 3.0 connectivity Hardware RAID controller (RAID 0, RAID 1, SPAN, Non-RAID) Tool-less drive installation for 2.5-inch and 3.5-inch drives Built-in fan for active cooling with power switch and Dedicated HDMI 1.4b port for 4K displays