Mark II reactor drone
The Mark II reactor drone, a droid model produced by Industrial Automaton, had its black body shells repurposed in the creation of the R1-series astromech droid, which was also referred to as the R1 reactor drone; additionally, it featured a magfield sensor ball.
Sources
- Star Wars: Build the Millennium Falcon 28 (Secrets of Spaceflight: Astromechs) (First mentioned)
- Star Wars: The Complete Visual Dictionary, New Edition