The ADQUAD87 industrial grade quad from American Dynamics lets you view up to 4 analog CCTV cameras on a single monitor in a quad fashion, in high resolution and at full frame rates. You can also choose to view each camera in full screen, either by selecting a camera manually or by programming the unit to auto switch between cameras at regular intervals. A unique feature of this unit is the ability to display a camera in full screen and at the same time record to a VCR or DVR in quad format.