The GAU-12/U is used by the United States, Italy and Spain, which mount the weapon in their attack jets such as the AV-8B Harrier II, airborne gunships such as the Lockheed AC-130, and land-based fighting vehicles.

The GAU-12/U cannon is operated by an 11 kW (15 hp) electric motor, or in external mounts supplied by a bleed air driven pneumatic system.

Also, the presence of a clockworking inertia-driven mechanical fuze in the mid-body, protects the round from shocks, misfires and cookoffs, making it safer to handle and fire.

The detachable pods are located and shaped to be interchangeable with the usual ventral strakes or fences under the Harrier, both serving to help trap a cushion of high-pressure air under the aircraft to add lift while in hover mode.

[citation needed] The Equalizer is also used in the AC-130U Spooky gunship, where one cannon is mounted on the port side, and the U.S. Marine Corps LAV-AD air-defense vehicle.

Intended as a higher-firepower alternative to conventional deck-mounted machine guns and cannon, the weapon employs the Navy's Mk 24 target designator and laser range finder for enhanced accuracy.