The projector is a Carl Zeiss ZKP 1 (Zeiss Kleinplanetarium No 1), serial number 256, capable of projecting a total of 5,000 stars down to the 6th magnitude. Additionally, the moon, planets and Milky Way can be displayed, as well as the various lines for astronomical navigation, i.e. the Vertical Circle, Meridian, Declination Circle, Ecliptic, Horizon, etc.
The ZKP 1 was produced in the hundreds between 1954 and 1992, most of them still in operation in various highschools and universities, mostly in Germany, Czech Republic and Slovakia, but they can be found all over the world even today.
The latitude can be adjusted between 0° and N 90° (the equator to the North Pole).
The projector can be used at standstill or run at various speeds to simulate the daily movement of the heavens (actually, of course, the rotation of the earth) so as to show, for example, the rising and setting of the stars.
The pinpoints of light depicting the stars is produced by a single 50W bulb and projected onto the dome through 31 lenses.