Type 99
Type 99 is an autocannon or artillery model.
Also recorded as Type 99 cannon.
Overview
20 mm autocannon aircraft armament.
In detail
It is associated with Japan.
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
“Type 99 cannon”, English Wikipedia, consulted as further reading
Consult the sourcereference work · Reputable secondary · Wikidata
Wikidata, structured authority record Q1151524: Type 99
Consult the source