MK3 grenade
MK3 grenade is a hand grenade or ammunition model.
In detail
It is associated with United States.
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
“MK3 grenade”, English Wikipedia, consulted as further reading
Consult the sourcereference work · Reputable secondary · Wikidata
Wikidata, structured authority record Q1822843: MK3 grenade
Consult the source