Cylindrical droids with multiple arms, FX medical droids assist other models, such as 2-1B surgical models, in surgical centers and on battlefields. FX-6 models monitor patients, perform tests, operate equipment and review medical procedures and techniques. An FX-6 droid supplied Darth Vader with a blood transfusion after the former Jedi’s crippling injuries on Mustafar and helped affix cybernetic legs to the flesh-and-blood stumps.