From Halopedia, the Halo wiki
The Repulsor is a piece of equipment compatible with the MJOLNIR (GEN3) armor. When deployed, the Repulsor emits an anti-gravity force in front of its user to launch objects and deflect projectiles.
The Repulsor is a usable piece of equipment in Halo Infinite. Players can deploy the Repulsor during combat. In the short duration of its deployment, the Repulsor can launch objects and deflect projectiles. These can include vehicles, rockets, overcharged bursts from a plasma pistol, grenades, other players, and even the user if directed at the floor or a wall.
List of appearances