The Imperial siege balloons were identified by a brown and red canopy that was powered by three gas jets. It also had a platform underneath connected by various wires, along with six laser cannons on the perimeter of the platform. The gas jets also acted as a weak point: blowing them up would result in them falling to the ground, as well as the wires connecting the canopy with the platform separating. The gaps between wires were large enough for an RZ-1 A-wing interceptor to fly between.
The Imperial siege balloons were utilized during the Galactic Civil War during the Battle of Taloraan, where they guarded various tibanna gas platforms containing both Imperial tibanna gas and civilian tibanna gas containers. 9 balloons were later utilized during the Rebel's Raid on Bespin. The Imperials had the siege balloons aim their laser cannons on the gas platforms, preferring to destroy the platforms than let the Rebels secure them. However, the Rebels exploited their weakness regarding the exposed gas jets and sent them tumbling down to the surface of Bespin.