Sonic grenade

Little is known about these grenades, other than that several of these were used by Colonel James Ackerson in testing the MJOLNIR Mark V armor on Reach, hidden amongst the Pillars of Loki and used in conjunction with Napalm Grenades.

Theories

• This grenade is similar to a Fragmentation Grenade in structure and detonation, except that it uses a miniature sonic boom rather than explosives. The grenade is not as effective as a Frag, but it is still effective and operative.
• The grenade is a non-lethal weapon used by Drill Instructors to teach Marines to keep their eyes peeled, hitting them with a loud sound that hurts their ears rather than actually causing them bodily harm. It would be one of the nicer booby traps used by DIs.they generate sound rather than hurt things

Trivia

• They're probably similar to the Star Wars Sonic Detonators as they use high frequency sounds to incapacitate targets.
• These grenades cannot be used by the player for they are not seen or used in the Halo Trilogy.
• Their use as a non-lethal measure means they could be compared to presently used flashbang grenades.