For 2G MMI system, the vehicle's multimedia system does not have an external audio input channel. After installing this module, the vehicle's multimedia system will add an AUX audio input channel, adding 3.5mm interface and RCA interface, which can make the sound of other playback devices. The multimedia transmitted to the car through the increased interface enhances the entertainment of the car multimedia. The optical fiber audio decoder is made according to the car CD protocol. It converts the analog sound signal into a digital audio signal and transmits it through the optical fiber. It solves the noise problem of sound input. The input of each channel is directly switched by using the MMI operation key. After installing this module, the automatically generates a virtual multi-disc CD system, CD1 or CD7 according to the different software versions of the MMI system of each model. Power supply mode of module power supply:Take power from the car insurance, this product does not need to be connected to ACC power supply, just connect the battery power supply and the ground wire. Module installation location:Vehicle co-pilot 6VCD CD Introduction to the module installation process: The optical fiber conversion cable of the product is inserted into the 6-disc CD optical fiber interface of the car, and the power supply of the product is connected, and the ground wire is connected. Precautions: This product is only suitable for 2G MMI system, the product only has one audio input function, no video input function AUX audio may also appear in CD2, and there will be more than 6 virtual disc drives in the car Fit:For Audio Optical Decoder. Special Features: add aux in Placement on Vehicle: FRONT Input voltage: 12V Fit for: for A6 A6L A8 2005-2009 Support system: 2G system Fuction: Add audio input(Aux in) color: Black Material: ABS Package Contents: 1x Audio Optical Decoder Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.