Connect two 3.5" SATA III hard drives to your computer through USB (Universal Serial Bus) 3.0 with UASP in a RAID array, & charge or connect USB (Universal Serial Bus) devices with the built-in 2-port USB (Universal Serial Bus) 3.0 fast charge hub. The S352BU33HR 2-Bay RAID Enclosure lets you build an external RAID array using two 3.5" SATA hard drives, & add it to your computer through USB (Universal Serial Bus) 3.0. For optimal performance from your SATA III drives, the external RAID enclosure supports a UASP-enabled USB (Universal Serial Bus) 3.0 host connection, which performs up to 70% faster than conventional USB (Universal Serial Bus) 3.0 when paired with a UASP compatible host controller. The RAID enclosure also lets you connect additional USB (Universal Serial Bus) 3.0 devices to your computer, through an integrated 2-port USB (Universal Serial Bus) 3.0 hub conveniently mounted on the front of the enclosure. The easy-to-reach hub also has fast charging capabilities, so you can charge your iPad, smartphone or other mobile devices as quickly as you would through a direct wall outlet connection. To help maintain safe operating temperatures for your hard drives, the 2-drive enclosure features a built-in cooling fan to ensure proper air circulation & prevent your SATA drives from over-heating. The enclosure features an integrated hardware RAID controller, which gives you the options you need to set up the array that best suits your storage application, including JBOD, Spanning, RAID 0, & RAID 1. To ensure compatibility with your computer system, the S352BU33HR supports all of the leading operating systems. UASP is supported in Windows 8, Mac OSX (10.8 or above), & Linux. In testing, UASP performs with a 70% faster read speed & 40% faster write speed over traditional USB (Universal Serial Bus) 3.0 at peak performance. At the same peak in testing UASP also shows an 80% reduction in required processor resources.