The VS0401 4-Port VGA Switch with Audio allows you to connect four audio/video source computers to a single monitor or projector with full audio and quickly switch between the devices for use. VS0401 built-in bi-directional RS-232 serial port for high-end system control, and advanced RS-232 control. With the ability to use high-end serial control devices via RS-232 commands allows the VS0401 to be controlled by secondary systems with advanced functions such as; port switching, auto switching, front panel pushbutton lock, and Power on Detection.