The HP 4-port USB 2.0 Hub expands the number of hubs on your computer. It allows you to connect up to 4 USB devices simultaneously with true plug and play connectivity. You can add or remove devices such as mice, keyboards and digital drives at any time - no need to power down or restart your computer. The hub is self-powered and provides sufficient power for cascading devices. By connecting devices using additional hubs, you can connect up to 127 USB devices to a single port on this hub. The HP 4-port USB hub transfers data at a rate of 480-Mbps to each port instead of sharing the bandwidth across the 4 ports. This hub is backwards compatible with USB 1.1-compliant computers.