Infusion grenade launcher
From Halopedia, the Halo wiki
These specialized grenade launchers are supplied with one Infusion grenade to each individual launcher. The weapons are arm-mounted, and wielded on both arms of the operator. The launchers also seem to have four finger-like attachments on the weapon; it's unknown what function these provide.
The Infusion Grenades Launcher were created following the creation of the infusion gel by Voridus.
Infusion Grenades Launchers are used by Brute Grenadiers in the the campaign of Halo Wars 2: Awakening the Nightmare and can be used in PvP multiplayer & Blitz for Voridus players.
List of appearances