Dynex DX-UC104 4-Port USB 2.0 PCI Desktop Card USB (Universal Serial Bus) specification Revision 2.0 Supports EHCI & UHCI Specifications Hot-Swappable and real Plug & Play capability Provides UP To 4 USB Root ports that work with high-speed 480Mbps,full-speed 12Mbps and low-speed 1.5Mbps Backwards compatible to all USB 1.1 peripherals