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.

   Features:
- Full duplex allows transfer of recording and playback video at the same time.
- 2x2 zoom
- 60 frames per second
- Real time clock
- Title generator
- On-screen display
- No boarder for full quad display
- 2H adaptive comb filters for Y/C separation