This item is one AUX cable for 2007-2009 S/CL Class 221/216 Chassis.
One end has bare audio pins and the other is a 3.5 mm male jack.
Head unit needs to be removed and main connection harness unplugged.
The AUX slots on the connector will be empty.
The pins at the one end of the cable will insert into the harness.
Instructions will be included on how this is done and what slots the AUX audio lines are on.
Please check your radios main audio drop down menu.
AUX needs to be one of the options.
If AUX is missing, The option will need to be activated by a Car dealer or shop.