Compliant with USB version 2.0 and backward compatible with USB 1.1.Transfer speed 1.5/12/480 Mbps.Compliant with OHCI specsification for USB Rev.1.0a.Providing 4 external and 1 internal ports as root hub to handle different devices.Daisy chain upto 127 simultaneous USB devices.32bit 33Mhz host interface compliant to PCI spec. 2.2.Supports PCI Power Management Interface spec. 1.1 .Supports Windows 98SE/ME/2000/XP.