Fully compliant with the Universal Serial Bus Specification,version 1.1,Compatible USB2.0 Single chip integrated USB hub controller with?embedded proprietary precessor. Supports four bus-powered/self-powered downs tream ports. Built-in3.3V voltage regulator allows single -5v opertion voltage.resultiong in reduced overall cost. Runs at 12MHz frequency. Driverless,hot plug & play Design with super streamline & mini, Blue LED show Support OS: Windows XP,2000,ME, 98SE, 98, Linux2.4 and Mac OS 8.5 or over version