ABUS Security-Center VGA Instructions D'installation page 13

8. Installation
Due to different twisting of the cable pairs and other parameters, there may be differences in the signal runtimes between the cable pairs. A big
difference in signal runtimes can result in poor convergence of colour values.
To reduce runtime errors, use the interference filter supplied.
!!! IMPORTANT: If interference filters are used at all, BOTH filters must ALWAYS be used.
13