The Lexar Pro DD512 Workflow is a storage drive with 512GB of space & USB (Universal Serial Bus) 3.0 interface. The drive offers fast read (450MB/s) & write (245MB/s) speeds & can be used as a standalone storage device with the included USB (Universal Serial Bus) cable, or with the Lexar Workflow HR2 Hub (not included, available separately). The capacity LEDs on the front indicate how much available storage the drive has free; each white LED represents 20% full & the blue LED is power & activity.