M383C Linear Shaped Charge Demolition Kit
From Halopedia, the Halo wiki
The M383C Linear Shaped Charge Demolition Kit is a UNSC explosive. Not much is known about this, although the name suggests it is not entirely a explosive, instead holding several of these perhaps small sized charges. It is also possible that it may function as a satchel charge.
Trivia
The mechanism by which the explosion of the Type-2 spike grenade is directed is similar to that of the M383C Linear Shaped Charge Demolition Kit.
Sources