Sollima's 3D-4X unit was a 3D-4X administrative droid that fulfilled a variety of roles for Sollima, an Aleena crime lord. This droid possessed crucial data concerning Sollima's ventures, encompassing both legitimate and illicit activities, information that could potentially be used to undermine him.
Billal Batross, in 1 BBY, leveraged his position within Sollima's gambling network to siphon funds from the Aleena's accounts. Sollima's accounting droid discovered this embezzlement, and Batross, in an attempt to conceal his actions, secretly sold the droid to representatives of the Galactic Empire. The Imperials intended to exploit the data stored within the droid's memory core to gain control over Sollima's casino world, known as the Hollow Moon. However, despite having stolen money from the crime lord, Batross still had an outstanding debt he was unable to pay. In desperation, he offered to retrieve the droid—which Sollima believed had been stolen by the Empire—in exchange for the debt's cancellation. He further requested that Sollima allow his old acquaintance, Han Solo, who also owed Sollima a debt he couldn't repay, to join him; the crime lord consented.
Working together, Solo and Batross successfully infiltrated the Moog Mot VI Imperial garrison. After locating the laboratory where the droid was being held, Solo subdued the lone technician present and instructed Batross to seize the droid and depart immediately. However, Batross had alternative motives and destroyed the droid's data core using his blaster pistol to conceal his theft from Sollima.
The droid's remnants were subsequently returned to Sollima, concealing a hidden explosive device, which was triggered by Billal Batross to aid the Empire in establishing dominance over the Hollow Moon.