USB Attached SCSI (UAS or UASP) is a computer protocol used to move data to and from USB storage devices such as hard drives (HDDs), solid-state drives (SSDs), and thumb drives. UAS depends on the USB protocol, and uses the standard SCSI command set. Use of UAS generally provides faster transfers compared to the older USB Mass Storage Bulk-Only Transport (BOT) drivers. UAS was introduced as part of the USB 3.0 standard, but can also be used with devices complying to the slower USB 2.0 standard, assuming use of compatible hardware, firmware and drivers.