Features: 1. Nice and practical accessory compatible with Mercedes Benz Smart 450 / Roadster / ForTwo / ForFour. 2. Operates seamlessly with any Bluetooth-enabled device without limiting car radio functionality. 3. Allows connection of an external audio source, enabling audio streaming from a smartphone to the car stereo system. 4. Pair your phone with the Bluetooth module, then select AUX on the radio to play music from your phone through the car speakers. 5. Multi-function support for memory card, USB flash drive, microphone, Bluetooth 5.0, AUX input, and high-fidelity audio output. Specification: Item Type: Bluetooth Music Adapter Material: Electronic components Compatibility: Supports memory card, USB flash drive, microphone, Bluetooth 5.0, AUX input, high-fidelity audio. Compatible CD Models: Mercedes Benz Smart Roadster / ForTwo Mercedes Benz Smart 450 (all models) with Grundig radio devices Four OEM Fitment: Mercedes Benz Smart Roadster 2003-2005 Mercedes Benz Smart ForTwo 2004-2010 Mercedes Benz Smart ForFour 2004-2010 Wiring Instructions: Connect the red power wire to 12V+ Connect the black power wire to 12V- Insert the 12-pin plug into the CD player jack (Please confirm the corresponding socket)