Supports both high-speed (480Mbps), full-speed (12Mbps), and low-speed (1.5Mbps) transfer rates Truly plug-and-play automatic system configuration USB and ACPI compliant OS Requirements: Windows 98SE/2000/ME/XP,Mac OS X or higher Bus Interface: USB 2.0 High Speed LED Indicators : Power ON (Red) LEDS one per USB downstream port (Activity green LED) . Case Material: ABS plastic Unit Size: 55mmx 100mm x 22mm Packing Accessories: USB 2.0 4-port HUB USB 2.0 cable (4pin x 4pin) Power adapter User Manual