Polarity sink

Polarity sinks were a piece of equipment that R2 series astromech droids could have built into the base of their chassis. The astromech droids R2-D2 and R2-R9 were both equipped with polarity sinks.Star Wars: The Complete Visual Dictionary, New Edition
==Sources==
*Star Wars: The Complete Visual Dictionary, New Edition 
==Notes and references==
Category:Droid parts