A stochastic field emitter was a piece of technology used by the Breen civilization to augment the shields of their warships.
History and specifications[]
In the year 2375, the warships used by the Breen Confederacy during the final battle of the Dominion War were equipped with stochastic field emitters, making it difficult for the Federation Alliance starships to breach the Breen's shields. (DS9 novelization: What You Leave Behind)