Sabrent USB 3.0 SuperSpeed 3 slot Memory Card Reader with Card Storage Box for Windows, Mac and Linux - Supports SD, SDHC, MMC/MicroSD/CF, and more (CR-CCU3) SuperSpeed USB 3.0 for maximum performance. Backward compatible with USB 2.0 hosts. Flashing activity LED indicates file transfer in process Easy to take, use and install, no additional software installation required. USB Bus Powered: no external AC power supply required