A quad is an accessory to your surveillance system that splits a video monitor into 4 screens. Without a quad you would only be able view one camera at a time. A quad is only needed when you are using more than one camera and using a VCR or VISEC to record or when you are only monitoring and not recording at all. Below are two examples of how a quad works:

This is a surveillance system that is monitored only:

This is a surveillance system recording and monitoring:

The quads that we carry are high resolution real time quads that support up to 4 cameras. You also have the ability to playback and zoom in on recorded video.

There are other products out there that can split a screen more than four ways. However, video quality worsens the more ways you split a screen.

A quad is not needed when using a Digital Video Recorder because DVRs have a built-in quad.