Retain the use of steering wheel or rear seat radio controls when replacing the factory head unit. Works with Pioneer and Sony radios with wired remote inputs. The SWI-PS also retains the use of heater control buttons on GM vehicles. Assign the buttons on the steering wheel to any of the 9 specific Pioneer functions. Volume Up, Volume Down, Mute, Track Up, Track Down, Source, Preset Up, Preset Down and Band. The SWI-PS has non-volatile memory which keeps all programming in memory.