The Matrox MicroQuad SDI to HDMI Multiviewer for 3G / HD / SD Feeds, in a body of about 5 x 5", lets you connect four cameras by SDI and then stream all four to share one HDMI monitor at the same time. The monitor will display four quadrants, with each showing one of your camera signals. The signals can be in 3G, HD, or SD format, but must all be of the same. 4K is also supported, via 3G or HD-SDI, and gets downscaled to 1080p. At any moment, you can choose one of the four quadrants to take up the whole screen, and you can toggle between the four in taking up the whole screen.

MicroQuad features all its controls on its body, and no computer is necessary to do what the above describes, but software can alternatively be used to carry out all the same functions. The software is a utility download available at no charge from Matrox. It is Windows-based and gets activated per a USB connection between the computer and MicroQuad.