USB DVI External Dual or Multi Monitor Video Adapter. This USB DVI Multi Monitor External Video Adapter turns an available USB 2.0 port into a DVI port - providing high quality, dual display or multi-monitor capability that can be used in a variety of laptop or desktop applications. Capable of running up to five additional displays from a single source simultaneously (using five USB2DVIE2 Multi Monitor External Video Cards), the adapter connects to a host computer through a USB 2.0 port to create a DVI connection that can be used to extend or mirror the desktop shown on the existing display - without having to open the computer case to install an additional video card.