It consists of a CCD detector that incorporates a wheel of up to 5 filters and a fisheye lens with a field of view of 180 degrees. The instrument is designed as a whole, as it contains everything you need to perform the measurements. Both, the computer and all of the control electronics, are integrated in the same box. The set is ready to withstand outdoor conditions, for which the instrument is housed in a thermally insulated box with different ventilation mechanisms to control the temperature and humidity inside the box.

The measurement process is fully automatic and needs no human operator. This instrument performs all the tasks necessary to obtain a measure of the brightness of the sky without having prior knowledge in astronomical image processing.