Z-400 splinter grenade

The Z-400 Pursuit Disruption Grid Generator (Z-400 PDGG), more commonly known as the splinter grenade, is a multi-purpose, area-denial grenade used by the Forerunners.

Specifications
The Z-400 splinter grenade is an area-denial grenade that can be utilized for both offensive and defensive purposes. When inert, the splinter grenade is a box-like device with six pyramidal projections from each face and glowing red-orange highlights that is visually similar to the near-detonation phase of the Z-040 pulse grenade. Once the grenade detonates, the splinter grenade splits and forms into a ionized lattice cloud of several floating orange "sparks". When someone comes into contact with this field, some or all of the sparks will detonate and disintegrate the unfortunate victim(s), just like the pulse grenade. The sparks appear to linger in the air for some time before dissipating. The ionized lattice additionally creates an electromagnetic pulse effect on vehicles that enter the cloud. Reports of a proximity fuse and airburst functionality with some splinter grenades are currently under investigation by the UNSC Navy's Office of Naval Intelligence.

Despite the grenade's separate UNSC designation, the splinter grenade appears to be one of many programmable settings for the Z-040 pulse grenade. Though it remains unclear who or what unlocked the device's new functionality, it is presumed that Promethean forces used the splinter grenade over the pulse grenade mode once it was clear that a Flood infestation was not an immediate tactical concern. UNSC analysis has not yet unlocked the mechanism for changing the grenade's mode nor discerned its other hidden functionality.

Gameplay
Due to the lingering effect and the fact the sparks are not very visible, it can be used as an effective trip mine, triggering when a player runs around a corner or pathway or backs into it by accident during a firefight. Due to its near-instantaneous detonation time when it comes into contact with a surface, it can effectively take out a player or enemy without giving them much time to dodge it by being thrown directly at them. It also has an EMP function that triggers upon coming into contact with a vehicle, which can facilitate boarding or hijacking action.

Trivia

 * In the Halo 4: Official Game Guide, the pulse grenade is portrayed in its near-detonation phase (cube with 6 spikes) which is identical to the splinter grenade's inert phase.
 * The shape of the splinter cloud is a cross and a hexagon when viewed from two different non-opposite lateral sides. In other words, looking at the cloud facing directly parallel to the "throw plane" will align the splinters in a cross shape, while walking around to be perpendicular to said plane, with an imaginary line connecting the player to the cloud's center, will show them in a hexagon.
 * This is also why the unused cluster grenade launcher's cluster bombs fall in two groups of three plus two more bombs falling perpendicularly; the bombs try to get into the same shape, but due to being affected by other forces, they fall.

List of appearances

 * Halo 5: Guardians