BB-series astromech droid

The BB-series astromech droid, also known as a 33 series astromech and often referred to as a BB unit or a rollie, was a model of the astromech droid manufactured by Industrial Automaton and active during the era of the Cold War, featuring a spherical body that allowed the droid to roll in any direction, with a head usually atop the body but not meant to be permanently physically attached to it (which would inhibit the droid's ability to roll around). Like earlier astromechs, the BB unit could fit into the droid socket of a starfighter. One notable BB unit was BB-8, owned by the pilot Poe Dameron.

The BB-series was a model of astromech droid. Powered by a selenium drive, these droids had an internal orbiculate motor that allowed their spherical bodies to roll across a variety of terrain, keeping their domed heads fixed on top with magnetic casters. Rather than keeping the head tethered by a single contact point, wireless telemetry allowed the two sections of the droid to communicate. The internal gyroscopic propulsion system was self-correcting, and surface sensors on the spherical body allowed the droid to travel across uneven environments such as deserts, with the benefit of its shell being sealed from dust contamination. For areas that proved too difficult for the orbiculate motor to traverse, BB units were equipped with compressed liquid-cable launchers that could tether and reel the droid in to hard-to-reach spots. As the droid's body faced in all directions at all times, it needed only to accelerate rather than turn. The BB's dense shell featured six swappable circular tool-bay disks that could be fitted with numerous forms of equipment, such as a magnetic-tipped bolt-spinner.