It's a rather accurate assembly (use sand paper to smooth some critical edges that, otherwise, could hamper the reciprocal slipping of some parts).
It's accompanied by a 38 pages booklet explaining the origin, rationale and use of the planetarium, with a number (100!) of possible "experiments", but unfortunately only in german: no editions, it seems, in other languages.
It's a real pity, because it could be used in schools (age 10-14, I think) worldwide.
The sky map enclosed is quite small, of little use (I think) and not-so-easy to assemble: make cuts very accurate !