XM82[]
As of this wiriting [11 MAR 2013] the article lists the 'XM82' as a stun grenade.
The XM82 was not a stun grenade insofar as I am aware (in other words, as far as Google has told me). Its design was that of a proposed Training Smoke Grenade.
This link provides information from 1992: http://www.dtic.mil/dtic/tr/fulltext/u2/a253895.pdf
The M84 (once known as the XM84) is a stun grenade, however. It has a unique hexagonal design, and a short 1-2 second fuse (M201A1 Mod. 2; non-fragmenting). However, the stun grenades shown in MGS1, MGS2, and MGS4 do not resemble the M84, nor do the preceding designs shown from MGS3, MPO, or PW.
As such, I have removed the XM82 designation from the article.
~ Orca*