The General Defense Unit battle droid, abbreviated as the GDU battle droid, was an upgraded model of former battle droids in service to the Hutt Empire. Adapted and improved by Hutt Doctor Lucius Stark, with the funding of the Hutt Empire, the droids wore experimental armor created by the Phoenix Corps, which Field Marshall of the Hutt Empire, Venator Furtificus, had destroyed and raided prior to the GDU battle droid's creation. GDU droids were used exclusively for protection of important Hutt figures such as Chairman Gorrbag, and for state security, and were not sold as retail models.