Bofors 57 mm m/47 aircraft gun
Bofors 57 mm m/47 aircraft gun is an autocannon or artillery model.
Also recorded as Bofors 57 mm aircraft gun L/50.
Overview
Swedish aircraft gun (1947-1958).
In detail
It is associated with Sweden.
Sources
Each source is named with the standing the house places on it, so the evidence can be weighed rather than taken on trust.
reference work · Reputable secondary · Wikipedia
“Bofors 57 mm m/47 aircraft gun”, English Wikipedia, consulted as further reading
Consult the sourcereference work · Reputable secondary · Wikidata
Wikidata, structured authority record Q10397339: Bofors 57 mm m/47 aircraft gun
Consult the source