The Antigravity pack is a propulsion equipment used by Elite Rangers and the Heretics to maneuver in any conditions between zero-gravity and normal-gravity (and possibly high-gravity as well, though this has never been demonstrated). It provides excellent mobility, and in no way hinders their combat effectiveness. In combat, this equipment allows Sangheili to easily dodge enemy fire and grenades to get in close or retreat when needed. They most likely work in a fashion similar to the Banshee's engines, encasing the user in an anti-gravity field that keeps them suspended in the air.