R-series

Droids of the R-series, such as R3-S6, U9-C4, and R4-P17 R-series designates a line of astromech droids that were produced by Industrial Automaton. This line included well-known R2 series droids, for example, R2-D2. Throughout the period known as the Cold War, R-series models were still in operation; some of these models had been functioning for nearly a century.