Steering Wheel control Primary harness adapters convert the commands from your car's steering wheel controls to a code that an aftermarket radio can recognize. A patch lead is also requires for SWC type systems based on the brand of head unit you have. for more details check out our you tube video. http://aerpro.com/video/control_harness_installation CHAR2C ALFA 159 2005-2011 ALFA SPIDER 2007 UP ALFA BRERA 2005-2010
