The Dorandan firing unit was a powerful energy weapon created by the Lanteans and located at the Doranda outpost, the site of Project Arcturus. In order to prevent a catastrophic overload, they built this device as a means of filtering the excessive energy in the event of containment failure.
Capable of rotating 360 degrees, the unit was able to automatically track and fire at ships in orbit, but does not, apparently, have the ability to differentiate between an enemy vessel and a friendly vessel without manual configuration. While the unit could be operated manually via a control console in the outpost itself, it was mostly automated; the only manual action absolutely necessary in the entire sequence of powering up, acquiring a target, and firing was the activation of the weapon's power source. The energy weapon was linked directly to the power generator; as there was no connection between it and the primary capacitor, the weapon was able to fire a continuous series of shots without pausing.
The energy bursts released by this weapon have proven to be powerful enough to single-handedly destroy an entire Wraith fleet, and it was stated that one direct hit would completely obliterate a Puddle Jumper (although this is not an altogether impressive feat, as jumpers have been severely damaged by weapons as weak as wraith spear rifles). The firing unit could not, however, penetrate the Asgard-designed shield of the Daedalus as easily, and the shield survived several direct hits. (SGA: "Trinity")