This is a MOST adapter for installation an aftermarket car radio/stereo in a Mercedes Benz that has a Fiber Optic CANbus system. This is for Mercedes vehicles that the factory Harmon Kardon upgraded sound system (look at your speakers to make sure).
Head Unit Replacement Compatibility:
Benz CLS.E.SLK/SL Class (W219, W211, W171 (<=2008)
Benz S/CL Class (W22)
HW: V3.0, SW: V1.8
Model # LZ230300023TY0543