21 cm SK L/40
21 cm SK L/40 is a naval artillery or artillery model.
Overview
Type of Naval gunRailway gunCoastal artillery.
In detail
It is associated with German Empire.
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
“21 cm SK L/40”, English Wikipedia, consulted as further reading
Consult the sourcereference work · Reputable secondary · Wikidata
Wikidata, structured authority record Q20008132: 21 cm SK L/40
Consult the source