[Warm Tips]: Some car models need an extra fiber optic loop adapter(: B0CKLFJLTH) even more. If it doesn't work after installating please confirm your original car comes with the original car navigation, satellite box and CDC or not. If your above compatiable vehicle has the factory navigation or amplifier system (For JBL BOSE Harman Kardon, etc.) installed, you need bypass these amplifier with the fiber optic decoder. Reduce installation fee,easy to install. All cables just need to be connected in front. The MOST box fits for Mercedes Benz E class W211 (E200/E220/E240/E270/E280/E300/E320/E350/E430/E500/E 55AMG/E550/E 63AMG)(2003-2008). It is compatiable with android radio and window CE stereo for Mercedes Benz CL(2004-2006), for Mercedes Benz CLS (2005-2008), for Mercedes Benz S class (2004-2006), for Mercedes Benz SL (2005-2008), for Mercedes Benz SLK (2005-2008). Decode for Bose Harman Kardon with optical interface. This optic fiber decoder box will keep your original car's optical fiber amplifier or for Harmon Kardon system or for Bose sound system work. Reduce installation fee,easy to install.