3D-4X
this was a series of administrative droids used during the early decades of the New Republic by Genetech, as a way to break into the protocol droid market. Unlike the 3PO series, the 3D-4X was developed as an expert in interstellar diplomacy, and was marketed to a specific set of customers. It was much more reliable and intelligent that comparable droids, such as the CZ-series. Unlike the 3PO series, the 3D-4X series had a personality that was described as aloof, or sardonic, but never prissy or self-important.