Z-040 pulse grenade

The Z-040 Attenuation Field Generator/Localized, also known as the pulse grenade, is a thrown Forerunner weapon that functions similarly to traditional grenades.

Overview
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. Its operation is similar in function to the power drain equipment of Halo 3.

Gameplay
As seen above, the Pulse Grenade operates very similarly to the power drain of Halo 3. However, unlike the power-drain, it does not 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.

Trivia
In the Halo 4: Official Game Guide it is mistakenly portrayed as a star-shaped device with six spikes. In the Halo 4: The Essential Visual Guide, it is shown to be a more box-like device with eight spikes. It is likely based off of the HUD icon when you have a pulse grenade on you, which also mistakenly portrays it as such.

List of appearances

 * Halo 4
 * Spartan Ops
 * Halo: Spartan Strike
 * Halo 5: Guardians