The Tech 4 PDV, alternatively referred to as Plexus Droid Vessels (PDV), functioned as communications and relay vessels, utilized by Imperial Intelligence courier droids.
These vessels, manned exclusively by droids and possessing minimal equipment, were primarily composed of engines and electronic systems. Serving to provide support for the Sector Plexus, PDVs were intentionally built with an appearance similar to mining droids. Their shape was that of a capsule, and they possessed the capability to transmit data throughout the galaxy.
One instance involved a PDV transporting information destined for an Imperial Intelligence sector headquarters, which was then intercepted by the forces of the Rebel Alliance. To avoid the Rebels capturing the data, the ship initiated a self-destruction sequence following the launch of an I2-CG droid carrying the vital intelligence. Even though the droid sacrificed itself, the Rebels were able to detect the I2 unit as it descended toward Goratak III. A battle then occurred on the planet between the Rebel squad and an Imperial team under the command of Feskitt Bobb.
Moff Jesco Comark made use of these vessels during the course of Operation Death-Hunter. Droids were employed to move the materials associated with the project in order to conceal the nature of the project's production. The Death-Hunter Cyborgs, which were the final result of the project, were transported by these courier droids.