They are dropped from the bays of Longsword Interceptors to mine locations within space from hostile incursions. They use both proximity and remote detonators and have very high explosive payloads. They may also have adhesive or magnetic quality to them as they were able to be attached to a remote piloted Pelican and later deployed from it. This may not be a regular armament as John-117 noticed that the Cryo-Tube had been removed to make way for this. During the Assault on Ascendant Justice, these were used to destroy the ship's Seraph Fighters, making way for their Longsword to land on the Covenant ship.