Z-040 pulse grenade
From Halopedia, the Halo wiki
The Z-040 Attenuation Field Generator/Localized (Z-040 AFG/L), also known as the pulse grenade, is a thrown Forerunner weapon that functions similarly to traditional grenades. One of the programmable settings is the Z-400 splinter grenade.
The pulse grenade was used by Forerunners to cauterize Flood strongholds composed of resilient Flood Super Cell accretions which quickly develop into a Gravemind. When inert, the Pulse Grenade is a box-like device with eight pyramidal projections and glowing yellow highlights. When thrown, its yellow patches invert into orange-glowing spikes, and it creates an area of effect that damages shields and health. It is designed to clear enemies from cover. Upon being thrown, it forcefully detonates and forms a hazardous ionization sphere which eventually collapses, destroying nearby targets and disintegrating them should they die. Its operation is similar in function to the power drain.
As seen above, the Pulse Grenade operates very similarly to the power drain of Halo 3, except without the ability to stop vehicles. The damage done by the weapon is low, and the shield/health stripping process is slow, enough so that it is nearly impossible to get a kill with it on a fully-shielded opponent. Instead, the grenade should be used similar to the Plasma Pistol; as a weakening device, to cause damage to an enemy and force them from cover, where they can be eliminated with ease via conventional means, or to deny an area or object (such as a dropped flag) to the enemy. However, it should be noted that a non-shielded opponent will die almost instantly from a pulse grenade field. Therefore, the weapon makes an excellent ambush tool for wounded opponents.
In the Halo 4: Official Game Guide it is portrayed as a box-shaped device with six spikes, each coming out of the faces of the cube. In the Halo 4: The Essential Visual Guide. This is actually the phase of the grenade shortly before it detonates, while the inert grenade is a box with spikes coming out of the corners as opposed to the faces. This near-detonation view is used as the icon on a player's HUD.
List of appearances