Genuine OEM Mercedes-Benz Start Ignition Switch Control Unit, part number A2139008620. This control unit is integral to the vehicle's ignition system, managing the starting sequence and power distribution. It is typically located within the dashboard assembly. The unit has dimensions of 0.2m x 0.06m x 0.1m and weighs 0.155 kg. Genuine OEM parts guarantee correct firmware and seamless integration with the vehicle's electrical system.