M9FB Flash Bang Grenades
A Flashbang grenade (also called a Stun grenade) is a special type of grenade used by the UNSC. Unlike Fragmentation grenades, these grenades are not intended for lethal use. Flashbangs use chemical reactions to produce an extremely bright flash of light and a very loud concussion blast when deployed, stunning targets, but doing very little physical damage to them. The primary purpose of a stun grenade is to temporarily blind and deafen the enemy.
RPG Notes: An enhanced concussion grenade designed to make a very loud noise and a bright flash in order to temporarily incapacitate a target. In addition to the normal concussion effects, all characters within 8 meters must make a D10 against their Constitution to avoid the other effects of the grenade, subtracting 1 from the die roll for each square (2 meters) they are from the burst point. Failure means that the characters are incapacitated (flash-blinded, temporarily deafened, and disorientated) for 24 phases (2 minutes). Success means that the character is incapacitated for only one phase (5 seconds).