BK 37
BK 37 is an autocannon or artillery model.
Also recorded as Bordkanone BK 3.7; BK 3.7.
Overview
37 mm autocannon aircraft armament.
In detail
It is associated with Germany.
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
“BK 3,7”, English Wikipedia, consulted as further reading
Consult the sourcereference work · Reputable secondary · Wikidata
Wikidata, structured authority record Q2658024: BK 37
Consult the source