Gravity wrench

The Gravity Wrench was a deleted Covenant weapon intended for an early version of Halo: Combat Evolved. It may have provided a basis for the Gravity Hammer. It may have also inspired the Spartan Laser, as the weapon must charge and then fires a strong beam. In addition to that, it appears to be act like a flamethrower, or other Support Weapons. It may have also been intended by the Covenant to be used as a maintenance device, although Bungie stated that it did more damage than repairs.

Trivia
The gravity wrench is very similar to the gravity gun in the Half-Life in which they can both move objects from a distance.