Models UPP 23/1, 23/2, 23/2s, 23/3

Made in Jena (GDR) between 1954 and 1964

UPP: Universal Projection Planetarium.

- 1954: UPP 23/1s: Volvograd (s: improved electric control)

- 1955: UPP 23/2s: Chorzow

- 1957: UPP 23/2: Beijing

- 1959: UPP 23/2s: St Petersburg

- 1960: UPP 23/3: Akashi

- 1960: UPP 23/2: Prague

- 1962: UPP 23/2s: Calcuta

- 1964: UPP 23/3: Riga