The USB-VGA Adapter delivers high quality video (up to 1920x1200) for a variety of applications and is capable of simultaneously running up to five additional displays from a single computer (using four USB2VGAPRO2 External Video Adapters). The adapter connects to a host computer through a USB 2.0 port, acting as an external VGA video card to either extend or mirror the desktop shown on the existing display - without having to open the computer.