Matrox DualHead2Go is an external multi-monitor upgrade that adds two monitors to your laptop or desktop computer (basically, a one-input, two-output DA). It connects to the video output of your PC or laptop and outputs uncompressed graphics and video across all monitors. DualHead2Go is available in DisplayPort, Digital, or even VGA. All of them support resolutions up to 3840×1200 (2x 1920×1200), but the displays attached to DualHead2Go must run at the same resolution because of EDID.
You can read all the specs here.