R4-K5

R4-K5 was an R-series astromech droid that accompanied Sith Lord Darth Vader, formerly Jedi Knight Anakin Skywalker, on missions for the Galactic Empire early during the Imperial Era. Once owned by a Jedi, R4-K5 was chosen for its dark hue by Vader to replace his former astromech droid, R2-D2.

R4-K5 occupied the droid socket of Vader's customized Eta-2 interceptor during missions to the worlds of Murkhana and Ostor. While competent at its duties, the droid never shared a close relationship with its Sith master as R2-D2 once had with Skywalker; R4-K5 was treated by Vader as simple equipment.

Text and facts from the “R4-K5” article on Wookieepedia, licensed under CC BY-SA 3.0. Modified for this site.