The B2 Battle Droid or Super Battle Droid was a vast upgrade over the B1 model, in intellect, strength, armor, and firepower. They first surfaced at the beginning of the Clone Wars during the battle of Geonosis and are the preferred soldiers of General Grievous. They were manufactured by Baktoid Combat Automata (which was owned by the Techno union). There were also other kinds of modified variants of B2 models such as the B2 rocket droid which was a model designed for Ariel combat. And others that were fitted with a canon in one of there arms.