Security camera networks require lots of cables. When laying long runs of cables installers usually have a choice between using CAT5 cable or coaxial cable. CAT5 cable is cheaper than coax cable, but has different electrical and physical characteristics.

You can't just connect the wires - you'll lose signal strength and picture quality. A video balun corrects this problem by balancing impedance and other electrical characteristics, which minimizes signal loss and noise.

It's important to use video baluns when sending video over Cat5 since the impedance specifications of Cat5, Cat5e and Cat6 are 100 ohms. Video requires 75 ohm impedance and you'll introduce artifacts to your video without a balun.