The MK3A2 offensive hand grenade, commonly referred to as the concussion grenade, is designed to produce casualties during close combat while minimizing danger to friendly personnel. The grenade is also used for concussion effects in enclosed areas, for blasting, or for demolition tasks. The shock waves (overpressure) produced by this grenade when used in enclosed areas are greater than those produced by the fragmentation grenade. It is, therefore, very effective against enemy soldiers located in bunkers, buildings, and fortified areas.
The concussion grenade has a significant advantage and disadvantage over fragmentation grenades: the lack of fragments. This lack of fragmentation device allows the grenade to be used in relatively close quarters where friendly forces would take casualties from fragments. The size of the charge in a concussion grenade is important because the shock waves produced by the explosion can indeed kill if the target is too close, and this effect is magnified in enclosed spaces. The concussion grenade in Firearms, however, is used primarily to disorient and temporarily disable the target.（たいてい鼓膜が破れるのだろう。）
