The second generation of star projectors was called Mark-II and exhibited the dumbbell shape for the first time. It had been designed almost parallel to the two units of Model-I. The spheres for the fixed stars have a diameter of 74 cm. The light bulb in the centre of each sphere gives a power of 1000 W and illuminates 16 star fields. The star images are realised by hand-perforated pinholes into very thin foils of copper (thickness: 0.015 mm), which are held by two glass plates. The spheres displays 8900 stars in total down to the 6.5 magnitude. Two motors with different velocities provide the diurnal and three motors the annual motion. Their combination supplies for a time progress in various speeds. One year can be travelled in about 70 seconds. The weight of the projector and its platform approaches 2.7 tons. 25 copies of this type were manufactured till the Second World War and sold throughout the world. Germany installed 11 devices, others were located in the USA (5), Italy (2), Japan (2), and USSR, Sweden, Belgium, France and Austria (1 each).