This item has been tested and is fully functional. This is a used OEM engine control unit (ECU) for Mercedes-Benz vehicles, specifically for the W209 CLK350, E350, and C350 models from 2006 to 2009. The ECU has a part number of A2721533779 and requires programming. It has a maximum amperage of 12A and a memory of EEPROM. The item includes mounting hardware and has a fitment type of direct replacement. It has 7 terminals and is made in Germany.