Plaxan sensors were a type of technology native to the Delta Quadrant, used mainly for defense training. They were typically difficult to acquire.

In 2372, Jal Razik hailed the USS Voyager and threatened to destroy the surface of a moon called Tarok, which was used by the Kazon-Ogla for training. On the moon's surface, an away team consisting of Captain Kathryn Janeway, Lieutenant Tuvok and Kes were searching for Commander Chakotay. Neelix told Razik that he may want to hold off on destroying the surface, since it was undoubtedly equipped with plaxan sensors, as he had traded a few to the Kazon. (VOY: "Initiations")