... transfer rate 1.5/12/480Mbps3. Supports up to 127 USB devices4. Extensively compatible with scanner, digital camera, digital vidicon, ... audio-system, display, U disk,5. Single chip integrated USB HUB controller with embedded proprietary processor6. 4 ports, and power ... up to 500mA each port7. USB bus power Supply ,No external power supply required8. Truly plug ...