While TESS-W can determine the night sky brightness in a broadband (panchromatic) it is interesting to determine the brightness in several bands to also get insight into the colour of the night sky. This is a step forward because variations in brightness and colour of the sky is a key observation when determining the impact of light pollution when a retrofit (change of lamp technology) is on the way.
TESS-4C is similar to a TESS-W but has 4 channels. The data are feed to the STARS4ALL repository and can also be read with local apps in your computer.

First version of TESS-4C showing the filter holders for custom 1 1/4 filters

Second version of TESS-4C and photometric bands.

The user can select photometric bands using 1.25" filters. The filter set transmission used allows to determine red, green (synthetic) and blue and also TESS-W band and UVIR650 nm band. For more information read "TESS-4C filters LICA report"

You can browse data in real time for stars701 at Villaverde del Ducado at the grafana panel

More info about setting up and connection at Observatorio Remoto blog