This enabled it to lock itself in place and made it nearly impossible to topple over. Its most outstanding device was its density projector, capable of increasing the droid's weight twenty-fold. Another addition to the rockets was that they could track multiple targets at once. Built into the left shoulder was a rocket launcher that was capable of delivering heavy damage. The right arm was equipped with a tight spray flamethrower, while the left sported a wide-spray plasma cannon. Two smaller arms wielded retractable rapid-fire blaster cannonsВ in the forearm. They were often used in place of droidekas, being far cheaper than the destroyer droids.ДЄn arsenal of many weapons gave this droid its bite. B3 units were used by the Trade Federation for frontline assaults against well defended targets. It stands at 4 meters and has a red sensor. The density projector also renders it immune to force attacks making it even more lethal.

The B3 also had a density projector to increase its weight, keeping it from falling over in combat. In addition, the ultra droid had a magazine of brilliant missiles located to the left of its large, neckless head. Two smaller arms, located underneath the primary limbs, featured deadly rapid-fire blasters, similar to the B2 battle droid.

The B3 had two large arms fitted with a flamethrower and a wide-spray plasma cannon. The B3 ultra battle droid was based on the B2 super battle droid model, though it was far larger and bulkier than the B2. The B3 ultra battle droid the epitome of separatists droid technology.