Reflex Cannons were powerful destructive energy beam weapons that were the product of Robotechnology. Construction of them required that they took significant space and resources of a starship in order to carry them. They functioned by large utilizing large firing booms to build up a destructive energy blast that was comparable to nuclear weapons.
Among the largest known Reflex Cannons was constructed on Earth in Alaska by the United Earth Forces and known as the Grand Cannon. By the Third Robotech War, they were replaced by the more compact and efficient Synchro Cannons that were discovered by the Robotech Expeditionary Force from Shadow Technology.