The 3C-series utility droid represents a line of maintenance droids produced by Duwani Mechanical Products. These droids were in operation before the Dark Wars and concurrently with the T3-series utility droid. During the Dark Wars' final year, a specific 3C-series unit, 3C-FD, assisted the droid T3-M4 in repairing the starship Ebon Hawk while on Peragus. Tragically, 3C-FD was subsequently destroyed by an HK-50 series assassin droid.
The utility droid of the 3C-series was a product of Duwani Mechanical Products, manufactured in the time frame linking the Jedi Civil War with the Dark Wars. Echoing other utility droid designs from Duwani during this era, the 3C droid was equipped with four wheeled legs. The front pair were connected to the droid's box-shaped body via rotating joints, enabling forward and backward movement for height adjustment. The unit, including its flat, rotating head, measured 0.96 meters in height. Its features included a versatile arm, auditory and sonar scanners, a radar eye, and visual sensors capable of processing all primary colors.
One such utility droid, 3C-FD, found itself aboard the light freighter Ebon Hawk before 3951 BBY. It was present when the ship made its escape from the Sith-infiltrated Republic cruiser Harbinger during that year. The escape left the Ebon Hawk severely damaged and adrift near the Peragus Mining Facility. There, 3C-FD collaborated with T3-M4, another utility droid from Duwani, to repair the vessel. Following the repairs, they piloted the Ebon Hawk toward the mining facility. However, before docking, an HK-50 series assassin droid concealed within the damaged ship relentlessly attacked 3C-FD, causing irreparable damage.
Within Star Wars Legends continuity, 3C-FD is the only 3C-series utility droid to appear. It featured in Star Wars: Knights of the Old Republic II: The Sith Lords, a video game released in 2004 and developed by Obsidian Entertainment. The 3C-series mirrors the appearance and functionality of the T3-series utility droid in the game, distinguished by a different colored sprite. Daniel Wallace's 2006 reference book, The New Essential Guide to Droids, includes an entry dedicated to 3C-FD, providing the droid series' technical specifications.