The next step in the history of the Spitz projectors was embraced with the model "A3P". It was produced in the 1960ies and 1970ies and became the most common commercial projector ever made. Mainly sold to colleges and schools, it was intended for 7 to 12 meter domes. The star device became spherical after the dodecahedron. It projects between 1500 and 6000 stars depending on the technical implementation. It uses both pinholes and lenses for the brightest stars. The planet gears are placed diametrically opposed to the star ball to balance its mass. On its base, the apparatus allows for the plug in of other devices for additional effects to be able to operate them from the control panel. Besides the A3P, the newer models A-4 and A-5 do exist, but their dispersal is small.