The R5-series astromech droid, also known as the R2-5, was a line of low-cost astromech droids built by Industrial Automaton. Based upon the success of prior astromech models, such as the wildly popular R2-series, Industrial Automaton intended the R5-series to cater to budget buyers at the cost of some functionality.
Astromech droids can aid in making repairs to a starship, and give a -3 modifier on Tech rolls when taken along on adventures.