[Source] The thermal annihilator bomb was an explosive device that could be detonated by a trigger remotely. The bomb was approximately the size of a clone trooper with its antenna, and had a front panel that could be taken off to access the explosives inside. The resulting explosion could easily destroy a medium-size building, and the bombs were used by Darts D'Nar during the Battle of Kiros as a tool to force the Galactic Republic to surrender. However, only one ever went off on Kiros, because the other bombs were destroyed by Anakin Skywalker and Ahsoka Tano, as Obi-Wan Kenobi distracted D'Nar by dueling him.