"They risked everything on the success of of their human replica series. Customers didn't take to them, and LeisureMech went under."
Den Dhur[src]

The BB-4000 was a Human replica droid model that was produced by LeisureMech Enterprises during the early years of the Galactic Empire. LeisureMech risked their entire enterprise on the success of the line, but the Human replica droids were a commercial failure and as a result, the company went under. LeisureMech sold off their remaining stock and the Toprawan resistance leader Degan Cor acquired two non-functional BB-4000 droids at a lower price. The droid were taken to be stored within the resistance base Mountain Home on Toprawa and the Rodian mech-tech Geri later repaired one of the units, so that it could house the droid brain of the protocol droid I-5YQ.