[Source] Spot sprayers' were tools used during the Galactic Civil War between the Galactic Empire and the Alliance to Restore the Republic. Some WED Treadwell repair droids were equipped with spot sprayers which they had built into the ends of some of their many arms. A WED unit which the Imperial Security Bureau used on the Wheel space station was equipped with a spot sprayer when it attempted to place a tracking beacon on the starship of a group of spacers working for the tech salvaging company IsoTech.